How to Secure Your Windows Computer and Protect Your Privacy

Security consultant Howard Fosdick has contributed the latest entry in the 2008 OSNews Article Contest: a highly detailed examination of security and privacy on the Windows platform, and how to use free software tools and a little knowledge to protect your privacy online.
Do you know that —

  • Windows secretly records all the web sites you’ve ever visited?
  • After you delete your Outlook emails and empty the Waste Basket, someone could still read your email?
  • After you delete a file and empty the Recycle Bin, the file still exists?
  • Your computer might run software that spies on you?
  • Your computer might be a bot , a slave computer waiting to perform tasks assigned by a remote master?
  • The web sites you visit might be able to compile a complete dossier of your online activities?
  • Microsoft Word and Excel documents contain secret keys that uniquely identify you? They also collect statistics telling anyone how long you spent working on them and when.

This guide explains these — and many other — threats to your security and privacy when you use Windows computers. It describes these concerns in simple, non-technical terms. The goal is to provide information anyone can understand. This guide also offers solutions: safe practices you can follow, and free programs you can install. Download links appear for the free programs as they are cited. No one can guarantee the security and privacy of your Windows computer. Achieving foolproof security and privacy with Windows is difficult. Even most computer professionals don’t have this expertise. Instead, this guide addresses the security and privacy needs of most Windows users, most of the time. Follow its recommendations and your chances of a security or privacy problem will be minimal. Since this guide leaves out technical details and obscure threats, it includes a detailed Appendix. Look there first for deeper explanations and links to more information.

Why Security and Privacy Matter

Why should you care about making Windows secure and private? Once young “hackers” tried to breach Windows security for thrills. But today penetrating Windows computers yields big money. So professional criminals have moved in, including overseas gangs and organized crime. All intend to make money off you — or anyone else who does not know how to secure Windows. Security threats are increasing exponentially. This guide tells you how to defend yourself against those trying to steal your passwords, personal data, and financial information. It helps you secure your Windows system from outside manipulation or even destruction. It also helps you deal with corporations and governments that breach Windows security and your privacy for their own ends. You have privacy if only you determine when, how, and to whom your personal information is communicated. Organizations try to gain advantage by eliminating your privacy. This guide helps you defend it.

The Threats

Windows security and privacy concerns fall into three categories —

  1. How to defend your computer against outside penetration attempts
  2. How Windows tracks your behavior –and how to stop it
  3. How to protect your privacy when using the Internet

The first two threats are specific to Windows computers. The last one applies to the use of any kind of computer. These three points comprise the outline to this guide.

There are many reasons someone or some organization out in the Internet might want to penetrate your Windows computer. Here are a few examples:

  • To secretly install software that steals your passwords or financial information
  • To enroll your computer as a bot that secretly sends out junk email or spam
  • To implant software that tracks your personal web surfing habits
  • To destroy programs or data on your PC

Your goals are to—

  • Prevent installation of malicious software or malware
  • Identify and eliminate any malware that does get installed
  • Prevent malware from sending information from your computer out into the web
  • Prevent any other secret penetration of your computer

1.1 Act Safely Online

Let’s start with the basics. Your use of your computer — your online behavior –significantly affects how easy it is to penetrate your PC. Practice safe web surfing. Handle your email safely. Follow these tips to reduce the chances that outsiders can penetrate your computer:

  • Don’t download free screensavers, wallpaper, games, or toolbars unless you know they’re safe. These often come with embedded malware. If you just can’t pass up freebies, download them to a directory where you scan them with your anti-virus and anti-malware programs before using them.
  • Don’t visit questionable web sites. Hacker sites, sexually explicit sites, and sites that engage in illegal activity like piracy of music, videos, or software are well known for malware. You could get hit by a drive-by — a malicious program that runs just by virtue of your viewing a web page.
  • Don’t open email or email attachments from questionable sources. These might install malware on your system. Dangerous email attachments often present themselves as games, interesting pictures, electronic greeting cards, or invoices so that you will open them. (If you get too much junk email, reduce it with these free programs .)
  • Don’t click on links provided in emails. These could direct you to a legitimate-looking but bogus web site designed to steal your personal information. Companies that protect their customers don’t conduct business through embedded links in emails!
  • Before you enter your online account name and password into any web site, be sure the web page is secure. The web page’s address should start with the letters https (rather than http ). Most browsers display a closed lock icon at the bottom of the browser panel to indicate a secure web site form.
  • Don’t give out your full name, address, phone number, or other personal information in chat rooms, forums, on web forms, or in social networks. (Section 3 on “How to Protect Your Privacy When Using the Internet” has more on this topic.)
  • The Appendix links to articles with more safety tips.

1.2 Install Self-Defense Software

To defend Windows, you need to install software that protects against several kinds of threats. This section describes the threats and the software that defends against each. Some programs provide protection against multiple threats. but no single program protects you from all kinds of threats! Compare any protective software you already have installed to what I describe here. To cover any gaps, this section recommends free software you can download and install. It provides download links for these free programs.

Firewall — Firewalls are programs that prevent data from coming into or leaving from your computer without your permission. Unsolicited data coming into your computer could be an attempt to compromise it; unauthorized data leaving your computer may be an attempt to secretly steal your data or spy on your activities.

Every Windows computer should run a firewall at all times when it is connected to the Internet.

I recommend downloading and installing a free firewall, such as ZoneAlarm, Comodo Firewall, Sygate Personal Firewall, or Jetico Personal Firewall. ZoneAlarm is especially easy to set up, since it is self- configuring. Find these and other free firewalls along with a quick comparative review here.

Windows ME, 98, and 95 did not come with a firewall. XP and Vista do. However, the XP and Vista firewalls have shortcomings. The XP firewalls (there are actually two versions) do not stop unauthorized outgoing data. This is unacceptable because if malware somehow got installed on your computer, it could send data out without you realizing it. Vista’s built-in firewall can stop unauthorized outbound data. But it does not do so by default. This how- to article shows that enabling this critical feature is not easy. I recommend installing a free firewall whether or not you have a Microsoft firewall. (It doesn’t hurt to run two firewalls.) Since the procedures for configuring Microsoft’s firewalls vary according to your Windows version and service pack level, see the Appendix for how to configure them.

Anti-Virus — Viruses are programs that are installed on your computer without your knowledge or permission. The damage they do ranges from acting as a nuisance and wasting your computer’s resources, all the way up to destroying your data or Windows itself. Anti-virus programs help identify and eliminate viruses that get into your computer. Free anti-virus programs include AVG Anti-Virus, avast! Anti-Virus Home Edition, and PC Tools Anti-Virus Free Edition. If you don’t already have an anti-virus scanner, download and install one of these, then run it regularly to scan your disk for any viruses. You can schedule the program to run automatically either through its own built-in scheduling facility or through the Windows Scheduler. Good anti-virus programs like these automatically scan data as it downloads into your computer. This includes emails you receive and any files you download.

Anti-Malware — In addition to viruses, there are many other kinds of programs that try to secretly install themselves on your computer. Generically, they’re called malware. They include:

Spyware It spies on your behavior and sends this data to a remote computer
Adware It targets you for advertisements
Trojans These scam their way into your computer
Rootkits These take over administrator rights and can do anything to your PC
Dialers These secretly use your communication facilities
Keyloggers These record your keystrokes (including passwords) and send this data to a remote computer
Botware This turns your computer into a bot or zombie, ready to silently carry out instructions sent from a remote server

Since no one program identifies and removes all kinds of malware, you need a couple in addition to your anti-virus scanner. Free programs for this purpose include AVG Anti-Spyware, Ad-Aware 2007 Free, Spybot Search and Destroy, and a-Squared Free Anti-Malware. I recommend running two anti-malware programs on a regularly-scheduled basis.

Anti-Rootkit — Rootkits are a particularly vicious form of malware. They take over the master or Administrator user rights on your PC and therefore are very effective at hiding themselves. Many of the anti-malware programs above provide some protection against rootkits. But sometimes a specialized detection program is useful. Rootkit detectors often require technical expertise but I can recommend two as easy-to-use, AVG Anti-Rootkit Free and Sophos Anti-Rootkit. Both require Windows XP or 2000 or newer.

Intrusion Prevention –Intrusion detection programs alert you if some outside program tries to secretly enter Windows by replacing a program on your computer. For example, an outside program might try to replace part of Windows or alter a program such as Internet Explorer. Free intrusion detection programs include WinPatrol, SpywareGuard, ThreatFire Free Edition, and ProcessGuard Free. Install one of them and it will run constantly in the background on your computer, detecting and preventing intrusions.

1.3 Keep Your Programs Up-to-Date!

All anti-malware programs require frequent updating. This enables them to recognize new kinds of malware as they are developed. The programs listed above automatically check for updates and download and install them as needed. (Each has a panel where you can verify this feature.) You must also keep Windows up-to-date. In Vista, the automatic feature for this purpose is called Windows Update. It is on by default. You can manage it through the Control Panel | Security | Windows Update option.

As Microsoft explains, they have broadened Windows Update into a facility they call Microsoft Update. The latter auto-updates a broader range of Microsoft products than does Windows Update. For example, it updates Microsoft Office. You can sign up for Microsoft Update at the Microsoft Update web site. In XP and Windows 2000, the auto-update feature was usually referred to as Automatic Updates. Manage it through Control Panel | Automatic Updates.

Beyond Windows, you must also keep the major applications on your computer up-to-date. Examples are Adobe’s Flash Player, Firefox, and RealPlayer. Most default to automatic updating. It’s a good practice to verify the auto-update setting right after you install any new program. Then you never need check it again. If you don’t know whether your system has all the required updates for your programs, run the free Secunia Software Inspector. It detects and reports on out-of-date programs and ensures all “bug fixes” are applied. If you need to download software updates for many programs, The Software Patch allows you to download them all through one web site.

1.4 Test Your Computer’s Defenses

You can test how well your computer resists penetration attempts by running the free ShieldsUp! program. ShieldsUp! tells you about any security flaws it finds. It also displays the system information your computer
gives out to every web site you visit. Section 3 on “How to Protect Your Privacy When Using the Internet” addresses this privacy concern. Test whether your computer’s firewall stops unauthorized outgoing data by downloading the free program called LeakTest.

1.5 Peer-to-Peer Programs Can Be Risky

Peer-to-peer programs share music, videos and software. Popular examples include BitTorrent, Morpheus, Kazaa, Napster, and Gnutella. Peer-to-peer (or P2P) networking makes it possible for you to easily download files from any of the thousands of other personal computers in the network. The problem is that by using peer-to-peer programs, you agree to allow others to read files from your computer. Be sure that only a single Folder on your computer is shared to the Internet, not your entire disk! Then, be very careful about what you place into that shared Folder. Some peer-to-peer programs use the lure of the free to implant adware or spyware on your computer. Other P2P systems engage in theft because they “share” files illegally. The popular PC Pitstop web site
tested major P2P programs for bundled malware in July 2005 and here’s what they found:

P2P Program: Adware or Spyware Installed:
Kazaa Brilliant Digital, Gator, Joltid, TopSearch
Ares NavExcel Toolbar
Bearshare WhenU SaveNow, WhenU Weather
Morpheus PIB Toolbar, Huntbar Toolbar, NEO Toolbar
Imesh Ezula, Gator
Shareaza, WinMX, Emule, LimeWire, BitTorrent, BitTornade None

The SpywareInfo web site offers another good list of P2P infections

. If you decide to install any peer-to-peer program, determine if the P2P program comes with malware before you install it. You greatly increase your personal security by not getting involved in the illegal sharing of music, videos, and software. File “sharing” in violation of copyright is theft. The Recording Industry Association of America has sued over 20,000 people for it as of mid-2006.

1.6 Don’t Let Another User Compromise Your Computer

Got kids in the house? A teen or younger child might violate the “safe surfing” rules above and you wouldn’t know it . . . until you get blindsided by malware the next time you use your computer. This article tells about a couple whose tax returns and banking data ended up on the web after their kids used P2P networking software the parents didn’t even know was installed. A spouse or friend could cause you the same grief.

If you are not the sole user of your computer — or if you do not feel completely confident that your computer is secure — consider what personal information you store. Do you really want to manage your credit cards, bank accounts or mutual funds from your PC? Only if you know it’s secure! (Read the agreements for online financial services and you’ll see that you are responsible for security breaches that compromise your accounts.) Some families use two computers: one for the kids and a secure one for the adults. They use the less secure computer for games and web surfing, and carefully restrict the use of the more secure machine. This two-computer strategy is appealing because today you can buy a used computer for only a hundred dollars. An alternative is to share one computer among everyone but set up separate user ids with different access rights (explained below). Ensure that only a single user id has the authority to make changes to Windows and restrict its use.

Never use a public computer at a computer cafe or the library for online finances or other activities you must keep secure.

1.7 Use Administrator Rights Sparingly

To install programs or perform security-sensitive activities on a Windows computer requires administrator rights. When you use administrator rights, any malware program you accidentally or unknowingly run has these rights — and can do anything on your system. In systems like Windows XP and Windows 2000, the built-in Administrator user id inherently has administrator rights. You can also create other user ids to which you assign administrator rights. Working full-time with a user id that has administrator rights makes you vulnerable!

In contrast, using an account that does not have administrator rights gives you a great deal of protection. So create a new user id without administrator rights and use it. Then use the Administrator id only when necessary. Windows Vista introduces a new feature called user account control that helps you avoid using administrator rights except when required. This feature prompts you to enter a password when you want to perform any action that requires administrator rights. While entering passwords may seem like a hassle, UAC is a big step towards a more secure Windows. Here is Microsoft’s introductory guide on this feature.

Early Windows versions –ME, 98, and 95 — don’t have a system of access rights. Whatever user id you use has the administrator powers. To keep these systems secure, all you can do is follow the other recommendations in this guide very carefully.

1.8 Use Strong Passwords

Passwords are the front door into your computer –and any online accounts you have on the web. You need to:

  • Create strong passwords
  • Change them regularly
  • Use different passwords for different accounts

Strong passwords are random mixes of letters, numbers, and punctuation (if allowed) that contain eight or more characters:

AlbqP_1793, pp30-Mow9, PPw9a3mc84

Weak passwords are composed of personal names or words you can find in the dictionary:

Polly28, Bigdog, alphahouse, wisewoman2, PhoebeJane

If keeping track of different passwords for many different accounts strikes you as impractical (or drives you nuts!) you might try a “password management” tool from any of the dozen free products listed here. If you set up a home wireless network, be sure to assign the router a password!

1.9 Always Back Up Your Data

One day you turn on your computer and it won’t start. Yikes! What now? If you backed up your data, you won’t lose it no matter what the problem is. Backing up data is simple. For example, keep all your Word documents in a single Folder, then write that Folder to a plug-in USB memory stick after you update the documents. Or, write out all your data Folders once a week to a writeable CD. You can also try an automatic online backup service like Mozy.

For the few minutes it takes to make a backup, you’ll insure your data against a system meltdown. This also protects you if malware corrupts or destroys what’s on your disk drive. If you didn’t back up your data and you have a system problem, you can still recover your data as long as the disk drive still works and the data files are not corrupted. You could, for example, take the disk drive out of the computer and place it into another Windows machine as its second drive. Then read your data — and back it up!

If the problem is that Windows won’t start up, the web offers tons of advice on how to fix and start Windows (see the Appendix). Another option is to start the machine using a Linux operating system Live CD and use Linux to read and save data from your Windows disk. If the problem is that the disk drive itself fails, you’ll need your data backup. If you didn’t make one, your only option is to remove the drive and send it to a service that uses forensics to recover data. This is expensive and may or may not be able to restore your data. Learn the lesson from this guide rather than from experience –back up your data!

1.10 Encrypt Your Data

Even if you have locked your Windows system with a good password, anyone with physical access to your computer can still read the data! One easy way to do this is simply to boot up the Linux operating system using a Live CD, then read the Windows files with Linux. This circumvents the Windows password that otherwise protects the files.

Modern versions of Windows like Vista and XP include built-in encryption. Right-click on either a Folder or File to see its Properties. The Properties’ Advanced button allows you to specify that all the files in the Folder or the single File will be automatically encrypted and decrypted for you. This protects that data from being read even if someone circumvents your Windows password. It is sufficient protection for most situations.

Alternatively, you might install free encryption software like TrueCrypt, BestCrypt or many others.

If you encrypt your data, be sure you will always be able to decrypt it! If the encryption is based on a key you enter, you must remember the key. If the encryption is based on an encryption certificate, be sure to back up or “export” the certificates, as described here. You might wish to keep unencrypted backups of your data on CD or USB memory stick.

Laptop and notebook computers are most at risk to physical access by an outsider because they are most frequently lost or stolen — keep all data files your portable computer encrypted.

1.11 Reduce Browser Vulnerabilities

As the program you run to access the Internet, your web browser is either your first line of defense or a key vulnerability in protecting your computer from Internet malware.

Will Your Browser Run Anybody’s Program? – From a security standpoint, the worldwide web has a basic design flaw –many web sites expect to be able to run any program they want on your personal computer. You are expected to accept the risk of running their code! The risk stems from both accidental program defects and purposefully malicious code. Some web sites require that you allow their programs to run their code to get full value from the web site. Others do not. You can find whether the web sites you visit require programmability simply by turning it off and visiting the site to see if it still works properly. Here are the keywords to look for in web browsers to turn off their programmability:

  • ActiveX
  • Active Scripting (or Scripting)
  • .NET components (or .NET Framework components)
  • Java (or Java VM)
  • JavaScript

Turn off the programmability of your browser by un-checking those keywords at these menu options:

Browser: How to Set Programmability:
Internet Explorer Tools | Internet Options | Security | Internet Custom Level
Firefox * Tools | Options | Content
Opera Tools | Preferences | Advanced | Content
K-Meleon Edit | Advanced Preferences | JavaScript
SeaMonkey Edit | Preferences | Advanced (Java) | Scripts and Plugins (JavaScript)

* Version 2 on

Internet Explorer Vulnerabilities — The Internet Explorer browser has historically been vulnerable to malware. Free programs like SpywareBlaster, SpywareGuard, HijackThis, BHODemon, and others help prevent and fix these problems.

Tracking Internet Explorer’s vulnerabilities is time-consuming because criminals continually devise new “IE attacks.” If you use Internet Explorer, be sure you’re using the latest version and that Windows’ automatic update feature is enabled so that downloads will quickly fix any newly-discovered bug. Some feel that IE versions 7 and 8 adequately address the security issues of earlier versions. I believe that competing free browsers are safer. Firefox is popular with those who want a safe browser that competes feature-for-feature with IE. K-Meleon couples safety with top performance if you don’t need all the bells and whistles of resource-consuming browsers like IE or Firefox. It runs very fast even on older computers.

1.12 Wireless Risks

Wireless communication allows you to use the Internet from your computer without connecting it to a modem by a wire or cable. Sometimes called Wi-Fi, wireless technology is very convenient because you can use your laptop from anywhere there is a invisible Internet connection or hotspot. For example, you could use your laptop and the Internet from a cafe, hotel, restaurant, or library hotspot.

But wireless presents security concerns. Most public hotspots are un-secured. All your wireless transmissions at the hotspot are sent in unencrypted “clear text” (except for information on web pages whose addresses begin with https). Someone with a computer and the right software could scan and read what passes between your computer and the Internet.

Don’t use public hotspots for Internet communications you need to keep secure (like your online banking).

Many people set up a wireless home network. You create your own local hotspot so that you can use your laptop anywhere in the house without a physical connection. Be sure the wireless equipment you use supports either the 802.11 G or 802.11 N standards. These secure wireless transmissions through WPA (Wi-Fi Protected Access) or WPA2 encryption. Do not base a wireless home network on equipment that only supports the older 802.11 A or 802.11 B standards. These use an encryption technology, called WEP (Wired Equivalent Privacy), that is not secure. You might inadvertently create a public hotspot! Freeloaders on your home network could reduce the Internet performance you’re paying for. Activities like illegal song downloads would likely be traced to you, not to the guilty party you’ve unknowingly allowed to use your network.

When you set up your wireless home network, assign your system a unique name, tell it not to broadcast that name, give it a tough new password, and turn on encryption. Specify that only certain computers can remotely use the network through MAC address filtering. Turn off your router and modem when you’re not using them. Expert advice varies on how to best secure wireless networks, so see the Appendix for more detail.

Are you aware that Windows tracks your behavior? It records all the web sites you ever visit, keeps track of all the documents you’ve worked on recently, embeds personal information into every document you create, and keeps Outlook email even if you tell Outlook to delete it. These are just a few examples of many. This section first tells how to securely delete your files, folders, and email so that no one can ever retrieve them. Then it describes the many ways in which Windows tracks your behavior. In some cases you can turn off this tracking. In most, your only option is to eliminate the tracking information after it has been collected.

2.1 How to Securely Delete Data

Let’s start with how to permanently delete data from your computer.

How to Securely Delete Files — When you delete a file in Windows, Windows only removes the reference it uses to locate that file on disk. Even after you empty the Recycle Bin, the file still resides on the disk. It remains on the disk until some random time in the future when Windows re-uses this “unused” disk space. This means that someone might be able to read some of your “deleted” files. (You can use free programs like Undelete+ and Free Undelete to recover deleted files that are still on your disk.)

To securely delete files, you need to over-write them with zeroes or random data. Free programs that do this include Eraser, BCWipe, and many others. After installing Eraser or BCWipe, you highlight a File or Folder, right-click the mouse, then select Delete with Wiping or Erase from the drop-down menu. This over-writes or securely deletes the data and so that it can never be read again.

Programs like Eraser and BCWipe also offer an option to over-write “all unused space” on a disk. This securely deletes any files you previously deleted using Windows Delete.

How to Securely Delete Email and Address Books –Even after you delete your Outlook or Outlook Express emails and empty the email Waste Basket, files containing your emails remain to be read by someone later. What if you want to permanently delete all your emails so no one could ever read them?

Whether this is possible depends on whether your computer is stand-alone or part of an organizational network. In an organizational setting, emails may be stored on central servers in addition to — or instead of — your personal computer. Many organizations store all the emails you ever send or receive on their servers so that you can never delete them. Here is a good discussion about whether you can really delete old emails in organizational settings.

If you have a stand-alone PC, emails are stored on your computer’s hard disk. To securely erase emails residing on your computer, locate the Outlook or Outlook Express files that contain your emails. Then use a secure-erase tool like Eraser or BCWipe to permanently destroy them. You can do the same with your Windows address book.

The files you need to securely erase may be marked as hidden files within Windows. To work with hidden files, you first need to make them visible. Checkmark Show Hidden Files and Folders under Start | Settings | Control Panel | Folder Options | View.

Now, search for file names having these extensions (ending characters) by using Windows’ Search or Find facility

.pst Outlook emails, contacts, appointments, tasks, notes, and journal entries
.dbx or .mbx Outlook Express emails
.wab Windows address book file

Note that Outlook stores much other information in the same file along with your obsolete emails. You can either erase all that data along with your emails by securely deleting the file, or, follow this procedure to securely delete the email while retaining the other information. For Outlook Express emails and Windows address books, just securely delete the files with the given extensions and you’re done.

How to Securely Delete All Personal Data on Your Computer –How can you securely delete all your personal information on an old computer before giving it away or disposing of it? This is difficult to achieve if you wish to preserve Windows and its installed programs. It takes a lot of time and there is no single tool that performs this function. The easiest solution is to overwrite the entire hard disk. This destroys all your personal information, wherever Windows hides it. Unfortunately it also destroys Windows itself and all its installed programs.

Be sure to copy whatever data you want to keep to another computer or storage medium first!

Several free programs securely overwrite your entire disk, such as Darik’s Boot and Nuke. The only possible way to recover data after running such programs is expensive physical analysis of the disk media, which may not be successful. Over-writing a disk is secure deletion for normal computer use.

2.2 The Registry Contains Personal Data

Windows keeps a central database of information crucial to its operations called the Registry. Our interest in the Registry is that it stores your personal information. Examples include the information you enter when you register Windows and Office products like Word and Excel, lists of web sites you have visited, login profiles required for using various applications, and much more. Upcoming sections discuss your personal information in the Registry how you can remove it. For now, let’s just introduce a few useful Registry facts —

  • The Registry is a large, complicated database (about which you can find tons of material on the web).
  • The Registry consists of thousands of individual entries. Each entry consists of two parts, a key and a value. Each value is the setting for its associated key.
  • The Registry organizes the entries into hierarchies.
  • This guide tells how to change or remove your personal information in the Registry by running free programs, but it doesn’t cover how to edit the Registry yourself –a technical topic beyond the scope of this paper.
  • Making a mistake while editing the Registry could damage Windows, so you should only edit it if you feel well qualified to do so. Always make a backup before editing the Registry.

2.3 Windows Tracks All the Web Sites You’ve Ever Visited

Windows keeps a list of all the web sites you’ve ever visited. You can tell Internet Explorer to eliminate this list through the IE selection Tools | Internet Options | Clear History. But Windows still retains it!

To view the web site history Windows retains, download and run a free program like Index.dat Spy. Windows records your web surfing history in a file named index.dat. (There are actually several index.dat files on your computer . . . I’ll describe what the others track later.) The index.dat files are special –you can not delete them or Windows will not start. Since Windows prevents you from changing or deleting these files, you need to run a free program to erase your web site history.

If you use Internet Explorer and have the default Auto-Complete feature turned on, your web surfing history is also kept in a second location — in the Windows Registry. (You’ll see web sites you’ve visited listed under the Registry key TypedURLs.) If you turn off Auto-Complete, Internet Explorer no longer saves your web history in the Registry. To turn off Auto-complete, go into Internet Explorer, then select Tools | Internet Options | Content | AutoComplete and un-check the box for auto-complete of Web addresses. Turning off Auto-Complete does not stop Windows from tracking your web site history in its index.dat files.

Several free programs securely erase your web site history from both the Registry and the index.dat files. Among them are CCleaner, Free Internet Windows Washer, CleanUp!, and ScrubXP, The shareware programs PurgeIE and PurgeFox are also popular. I’ve found CCleaner to be both thorough and easy-to-use.

2.4 Windows Leaves Your Personal Information in its Temporary Files

Windows, web browsers, and other programs leave a ton of temporary files on your computer. Some hold web pages you’ve recently viewed, so that if you go back to that web page, you’ll be able to view it quickly from disk instead of downloading it again from the web. Other files are used by Windows and its applications as temporary work areas. Still others are used to log program actions or store debugging information. These temporary files sometimes contain personal information. For example, web page caches contain copies of web forms into which you’ve entered passwords or your credit card number. You may not wish to disclose the web pages, videos, images, audio files, and downloaded programs you’ve viewed lately. The trouble is that these temporary files are not erased after use. Some remain until the system needs that disk space for another purpose. Others hang around forever, unless you know to clean them.

The free programs above that erase your web history also erase these temporary files and cache areas. Find more free programs here and a review of the best commercial programs here.

2.5 Your “Most Recently Used” Lists Show What You’re Working On

Windows tracks the documents you’ve recently worked with through its Most Recently Used or “MRU” lists. MRU lists are kept by Microsoft Office products like Word and Excel, as well as applications from other vendors. Window’s Start | Documents list also shows documents you have recently worked with. Products keep MRU lists for your convenience. They help you recall and quickly open documents you’re currently working on. These lists also offer the perfect tracking tool for anyone who wants to find out what you’ve been doing on your computer. They provide a ready-made behavioral profile. Windows and its applications keep many more MRU items than you might expect –thousands of them, if you have never cleared the lists. Free program MRU Blaster cleans out these lists. Other free programs like Ad-Aware 2007 Free, CCleaner, and Free Internet Windows Washer erase many of the lists. Run an MRU cleaner whenever you like. Remember that after you clean the lists, the “quick picks” of your recent documents will not appear in Word, Excel, or other products.

2.6 Product Registration Information May Be Hard to Change

When you register Windows, Microsoft Office, or other products, that information is stored in the Windows Registry. It can be read from there by any program or person who reads the Registry. Registering a software product shows your legal ownership of the product and may be required to receive product support and updates. However, changing or eliminating the personal registration information later might be difficult. Some products have an Options or User Information panel in the program where you can easily change the product registration. But most require you to either directly edit the Windows Registry or even de-install the product to change or remove the personal registration data. Consider carefully what you enter into any product’s registration panel when installing it. You may not be able to change it later. If you know you won’t need vendor support or updates and the product license permits it, you could enter blank registration information.

2.7 File “Properties” Expose Personal Data

Right-click on any Microsoft Word, Excel, or Powerpoint file, and select Properties from the pop-up menu. You’ll see a tabbed set of panels that keep information about the file. (For some versions of Microsoft Office, you need to click the Advanced button to expose all the information.) You’ll see that Microsoft Office saves information about the file such as: Who created it

  • The company at which it was created
  • The name of the computer on which it was created
  • A list of all who have edited it
  • When it was created and when it was last saved
  • The number of times it has been edited
  • Total editing time
  • Comments
  • A hidden revision log
  • Recent links used in the file
  • Various statistics about the size of the file, the word count, etc

The information varies according to the type of file you view (Word, Excel, or Powerpoint) and the version of Microsoft Office that was used to create and edit the file. You can’t see everything Office saves in the Properties panel –some of it remains hidden from your view.

You can change some of the Properties information by right-clicking on the file name, then editing it. Or alter it while editing the document by selecting Edit | Properties.

Other data is collected for you whether you want it or not, and you can not change it. Should you care? It depends on whether it matters if anyone sees this information. In most cases it doesn’t. But sometimes this data is private and its exposure matters. Just ask former U.K. Prime Minister Tony Blair. He took Britain to war against Iraq in 2003 based on the contents of what he presented as his government’s authoritative Iraq Dossier. But this Word file’s properties exposed the high-powered dossier as the work of an American graduate student, not a team of British government experts. A political firestorm ensued.

Microsoft offers manual procedures that minimize Office files’ hidden information. But these are too cumbersome to be useful. Microsoft eventually developed a free tool to cleanse Office documents created with Office 2002 SP2 or later. But restrictions limit its value. The free tool Doc Scrubber is an alternative for cleansing the Properties metadata from Word files.

Whichever tool you use, you must run it as your last action before you distribute your finished Office document. Cleansing Microsoft Office files is inconvenient and it’s difficult to remember to do it. Those who require “clean” office documents are advised to use the free office suite that competes with Office, called The OpenOffice suite does not require personally-identifying Registration information and it gives you control over the Properties information. It reads and writes Microsoft Office file formats. (I edited this document interchangeably with OpenOffice and several different versions of Microsoft Word, then created the final PDF file using OpenOffice.) Read reviews of OpenOffice here.

2.8 Microsoft Embeds Secret Identifiers in Your Documents

Windows, Windows Media Player, Internet Explorer, and other Microsoft applications contain a number that identifies the software called the Globally Unique Identifier or GUID. Microsoft Office embeds the GUID in every document you create. The GUID could be used to trace the documents you create back to your computer and copy of Microsoft Office. It could even theoretically be used to identify you when you surf the web. The free program ID-Blaster Plus can randomize (change) the GUIDs embedded in Windows, Internet Explorer, and Windows Media player. The free program Doc Scrubber erases GUIDs contained in a single Word document or all the Word documents in a Folder.

If you’re concerned about secret identifiers embedded in your Office documents, use the OpenOffice suite instead. This compatible alternative to Microsoft Office doesn’t embed GUIDs in your documents nor does it require personal registration and Properties information.

2.9 Chart of Tracking Technologies
I’ve discussed the major areas in which Windows and other Microsoft products track your computer use. In most cases you can not turn off this tracking. But the free programs I’ve described will delete the tracking information. The chart below summarizes where and how Windows and other Microsoft products track your behavior. Many items apply only to specific software versions. A few functions report your behavior back to Microsoft. Examples include when Windows Media Player sent your personal audio and video play lists to Microsoft and the company’s attempts to use the Internet to remotely cripple Windows installs it considers illegal.

— Where Windows Tracks Your Behavior —

Application Logs Records on how often you run various programs
Clipboard Data Data you’ve copied/pasted is in this memory area
Common Dialog History Lists Windows “dialogs” with which you’ve interacted
Empty Directory Entries File pointers unused by Windows but still usable by those with special software
Error Reporting Services Reports Windows or Microsoft Office errors back to Microsoft
File Slack Space “Unused” parts of file clusters on disk that may contain old data
File Properties Office document Properties contain your personal editing information and more
Find/Search History Lists all your Find or Search queries (used by Windows auto-complete)
GUIDs Embedded secret codes that link Office documents back to your computer
Hotfix Unistallers Temporary files left for un-doing Windows updates
IIS Log files Logged actions for Microsoft’s IIS web server
Index.dat Files Secret files that list all web sites you visit and other data
Infection reporting Microsoft’s Malicious Software Removal Tool reports infections to Microsoft
Last user login Tracks the last user login to Windows
Microsoft Office History MRU lists for Office products like Word, Excel, Powerpoint, Access, and Photo Editor
Open/Save History List of documents or files for these actions
Recently Opened Doc. List MRU list accessible off Start | Documents
Recycle Bin Deleted files remain accessible here
Registration of MS Office Registration information is kept in the product Options, Splash panels, and Registry
Registration for Windows Registration information is kept in the Registry
Registry Backups Registry backups may contain personal data you may have edited out of the Registry
Registry Fragment Files Deleted or obsolete data in the Registry that remains there
Registry Streams History of Explorer settings
Remote Help Allows remote access to your computer for Help
Run History Lists all programs you have run through Windows Run box
Scan Disk Files Files output from SCANDISK (may contain valid data in *.chk files)
Start-Menu Click History Dates and Times of all mouse clicks you make for the Start Menu
Start-Menu Order History Records historical ordering of Start Menu items
Swap File Parts of memory written to disk
Temporary Files Temporary files used during program installation or execution
Time synchronization service Synchronizes your computer clock by remote Internet verification
User Assist History Most used programs on the Start Menu
Windows Authentication Identifies Windows license validity to Microsoft
Windows log files Trace results of Windows actions and installs
Windows Media Player content Automatically downloads content-licenses through the Internet
Windows Media Player History Lists the Most Recently Used (MRU) files for Windows Media Player
Windows Media Player metadata Automatically retrieves metadata for audio CDs through the Internet
Windows Media Player Playlist Your Windows Media Player play lists
Windows Media Player statistics Sends your Windows Media Player usage statistics to Microsoft

— Where Internet Explorer Tracks Your Behavior —

Auto-complete form history Everything you type into web site forms (inc. passwords & personal information)
Auto-complete for passwords Convenient but less secure
Cookies Data web sites store on your computer (sometimes used to track your surfing habits)
Downloaded files Files you download while using the Internet
Favorites Web sites you list as “favorites” in your browser
Plug-ins Information saved or cached by third-party software that “plugs into” Internet Explorer
Searches Searches are retained by both IE and search engines
Temporary files (cache) Web pages the browser stores on disk
Web site error logs Errors encountered during web site retrieval
Web sites visited All the web sites you have ever visited are stored in the Registry and index.dat files

This comparative review rates ten commercial products versus many of the above functions.

Privacy is the ability to control when, how, and to whom your personal information is given. Privacy is power. Losing your privacy means losing personal power. This section offers tips and technical advice to help you protect your privacy when using the Internet. It applies whether you use Windows or some other operating system, like Linux or Apple’s Mac OS. Web privacy is a fast-moving area in which technologies and laws are in flux. This guide can no more guarantee you absolute privacy than it can guarantee you a completely secure Windows. But if you follow our tips you’ll minimize your privacy exposure.

3.1 Limit the Personal Information You Give Out

Before entering personal information into a web site form, a social network, or a forum, read the site’s Privacy Policy and Terms of Use. If they’re legalistic and hard-to-read, chances are they have more to do with harvesting your personal data than protecting it. Many agreements are written so that they can be changed at any time. This makes any assurance of protection for your personal data worthless because the web site could simply change the agreement after you’ve provided the information. Some agreements even include fine print by which you agree to the installation of malware on your computer!

Few privacy policies guarantee that information will be destroyed as it ages. Once given out, information tends to live forever. Few privacy policies give you any legal rights if your information is lost or stolen. In 2007 alone, over 162 million personal records were reported lost or stolen in the United States. (Yet it remains legal for companies to buy and sell your social security number and personal data.)

Once you post personal information on the web, you lose control over how that information is used. Changes to the “context” in which that data is used can harm you. An example is the information students enter into social web sites like MySpace or Facebook for their friends’ amusement, only to find it resurfacing later to harm their employment opportunities or their careers. Both sites offer privacy controls that easily allow individuals to avoid such consequences — but most users don’t apply them.

The selling of personal data is a multibillion dollar, largely-unregulated business in the United States. It’s an entire industry called information brokering.

People who give out their personal data expose themselves to manipulation or worse. Even the U.S. government is researching the harvesting of personal data from social networking sites for public surveillance. And why not? People voluntarily post the information. Fans of social networking will consider these cautions anachronistic. Please read how people expose themselves to manipulation or harm by posting personal data, found in authoritative books such as The The Digital Person, The Soft Cage, or The Future of Reputation: Gossip, Rumor, and Privacy on the Internet.

We need government regulation to enforce minimal rights for social network users, much the way we have consumer-protection legislation for credit cards. Meanwhile, protect yourself by educating yourself. Tiny bits of information can be collected and compiled by web computers into comprehensive profiles. If an organization can collect enough small bits of information –for example, just the names of all the web sites you visit — they can eventually develop a complete picture of who you are, what you do, how you live, and what you believe. Privacy is power. You give away your personal power when you give out personal information. You assume risk you can not measure at the time you assume it.

3.2 Don’t Let Web Sites Track You

Cookies are small files that web sites store on your computer’s disk. They allow web sites to store information about your interaction with them. For example, they might store the data required for you to purchase items across the several web pages this involves. However, cookies –originally called tracking cookies –can also be used to track your movement across the web. Depending on the software using them, this data could be used to create a detailed record of your behavior as you surf. The resulting profile might be used for innocuous purposes, such as targeted marketing, or for malicious reasons, like spying.

Most browsers accept cookies by default. To retain your privacy, set the browser not to accept any cookies other than exceptions you specify. Then only web sites you approve can set cookies on your computer. A few web sites won’t let you interact with them unless you accept their cookies — but most will. You can also set most browsers to automatically delete all cookies when you exit. This allows web sites to set the cookies required for transactions like purchasing through the web but prevents tracking you across sessions. To manage cookie settings in your browser, access these panels:

To turn cookies on or off —

Internet Explorer Tools | Internet Options | Privacy | Advanced
Firefox (version 2 on) Tools | Options | Privacy | Cookies
Opera Tools | Quick Preferences | Enable Cookies
K-Meleon Tools | Privacy | Block Cookies
SeaMonkey Edit | Preferences | Privacy & Security | Cookies

To allow specific web sites to set cookies —

Internet Explorer Tools | Internet Options | Privacy | Edit
Firefox Tools | Options | Privacy | Cookies | Exceptions
Opera Tools | Preferences | Advanced | Cookies | Manage cookies
K-Meleon Edit | Preferences | Privacy
SeaMonkey Tools | Cookie Manager

To “clear” (erase) all cookies currently on your computer for the specified browser —

Internet Explorer Tools | Internet Options | General | Delete Cookies
Firefox Tools | Clear Private Data
Opera Tools | Preferences | Advanced | Cookies
K-Meleon Tools | Privacy | Clear Cookies
SeaMonkey Tools | Cookie Manager | Manage Stored Cookies | Remove All Cookies

To automatically clear all cookies whenever you exit the browser —

Internet Explorer Not available
Firefox Tools | Options | Privacy | Cookies | Settings. . .
Opera Tools | Preferences | Advanced | Cookies
K-Meleon Tools | Privacy | Settings. . .
SeaMonkey Not available

CookieCentral has more information about cookies and how to manage them. Other tracking mechanisms include web bugs, Flash cookies, third-party local shared objects. These are less common than cookies and rather technical so follow the links and see the Appendix if they concern you.

3.3 Email Privacy
Sending an email over the Internet is like sending a postcard through the mail. Anyone with the ability to intercept it can read it. There is evidence that the United States government either scans or compiles data about every email sent in the country.

You can keep the contents of your personal communications private by encrypting your email. This web page provides information and free downloads. It also lists programs that will encrypt your online interactive Chat. This article illustrates how to set up secure email step by step. The trouble with encrypted email is that both the sender and the recipient must participate. It’s impractical to send encrypted email to people you don’t know. Or to anyone using a different encryption system. The major email programs could easily support standardized, universally-compatible encryption in their clients — but don’t.

Remember that emails are often the basis for phishing scams –attempts to get you to reveal your personal information for nefarious purposes. Don’t respond to email that may not be from a legitimate source. Don’t even open it. Examples include claims you’ve won the lottery, pleas for help in handling large sums of money, sales pitches for outrageous deals, and the like.

Email may also be spoofed –masquerading as from a legitimate source when it is not. Examples are emails that ask you to click on a link to update your credit card account or those that ask for account information or passwords.

Legitimate businesses are well aware of criminal misuse of email and don’t conduct serious business transactions through mass emailings!

Many people use two email addresses to avoid spam and retain their privacy. They use one account as a “junk” email address for filling out web site forms, joining forums, and the like. This email address doesn’t disclose the person’s identity and it collects the spam. They reserve a second email account for personal communications. They never give this one out except to personal friends, so it remains spam-free.

3.4 Web Surfing Privacy

If you tested your computer as suggested earlier using ShieldsUp!, you saw that it gives out information to every web site you visit. This data includes your Internet protocol address, operating system, browser version, and more. Your Internet protocol address or IP address is a unique identifier assigned to your computer when you access the Internet. Web sites can use it to track you. Your Internet Service Provider or ISP assigns your computer its IP address using one of several different techniques. How traceable you are on the web varies according to the technique your ISP employs along with several other factors, such as whether you allow web sites to set cookies and whether your computer is compromised by malware.

One way to mask who you are when web surfing is to change your IP address. Anonymizing services hide your IP address and location from the web sites you visit by stripping it out as your data passes through them on the way to your destination web site. Anonymizers help hide your identity and prevent web sites from tracking you but they are not a perfect privacy solution (because the anonymizer itself could be compromised). is a very popular free anonymizing service. Find other free services here and here.

A more robust approach to anonymity is offered by free software from JAP and TOR. Both route your data through intermediary servers called proxies so that the destination web site can’t identify you. Your data is encrypted in transit, so it can not be intercepted or read by anyone who scans passing data. Services like JAP and TOR present two downsides. First, your data is sent through intermediary computers on the way to its destination, so response time slows. Whether you still find it acceptable depends on many factors; the best way to find out is simply to try the software for yourself.

These systems still leave you exposed to privacy violations by your Internet Service Provider. Your ISP is the your computer’s entry point into the Internet, so your ISP can track all your actions online. For this reason, when the Bush administration decided to monitor American citizens through the Internet, they proposed legislation that would force all ISPs to keep two years of data about all their customers’ activities. The government’s current web surveillance program made it necessary for major ISPs like AT&T/Yahoo to change its privacy policy in June 2006 to say that AT&T –not its customers –owns all the customers’ Internet records and can use them however it likes. Repeated congressional proposals to immunize ISPs from all legal challenges only make sense if the ISPs colluded with the government in illegally monitoring Internet activities.

3.5 Search Privacy

Web sites that help you search the web are called search engines. Popular search engines like Google, Yahoo!, and MSN Search retain records of all your web searches. Individually, the keywords you type into search engines show little. But aggregated, they may expose your identity. They may also expose your innermost thoughts –or be misinterpreted as doing so. Here’s an example. Say the search engine captures you entering this list of searches —

  • kill wife
  • how to kill wife
  • killing with untraceable substance
  • kill with unknown substance

Someone might interpret these searches as indicating that you should be reported to the authorities because you’re planning a murder. But what if you were simply doing research for that murder mystery you always wanted to write? You can see need for search privacy. Do you have it? The federal government has demanded search records from major search engines like Google, AOL, Yahoo, and MSN.

While the government claims these requests are to combat sexual predators, most analysts believe they are for public surveillance and data mining. America Online (AOL) accidentally posted online 20 million personal queries from over 650,000 users. The data was immediately gobbled up and saved in other web servers. Although AOL apologized and quickly took down their posting, this data will probably remain available forever somewhere. Some people can be identified by their “anonymous” searches and have been harmed as a result of this violation of their privacy.

The AOL incident is a wake-up call to those who don’t understand how small pieces of information about people can be collected by Internet servers, then compiled into revealing dossiers about our individual behaviors. This principle doesn’t just apply to search engines. It extends to the web sites you visit, the books you buy online, the comments you enter into forums, the political web sites you read, and all your other web activities. The AOL debacle demonstrates that web activities many assume to be anonymous can sometimes be traceable to specific individuals.

The Electronic Frontier Foundation’s excellent white paper Six Tips to Protect Your Search Privacy offers these recommendations to ensure your search privacy —

  • Don’t include words in your searches that identify you personally (such as your name or social security number)
  • Don’t use your ISP’s search engine (since they know who you are)
  • Don’t “log in” to search engine web sites
  • Don’t let the search engine set cookies
  • Don’t use the same IP address all the time
  • Use anonymizers like JAP or TOR to thwart traceability

If you use Windows, Microsoft Office, and Internet Explorer, you need to be aware of how these products could compromise your security and privacy. You can minimize these issues by following this guide’s recommendations. Anyone can achieve sufficient security and privacy when using Windows. But you must follow safe practices and download and install a number of programs. Your privacy is not a design goal of Windows. It is up to you to make Windows secure and private.

Appendix: Further Information and Links

PDF and Appendix: For a printable and archivable version of this article, please download the PDF version. It is released under the OPL (Open Publication License) and may be freely reproduced and distributed but not altered prior to redistribution. This product is distributed at no cost under the terms of the Open Publication License with License Option A — “Distribution of modified versions of this document is prohibited without the explicit permission of the copyright holder.”

The PDF document also has a detailed Appendix with links to much more online information.

Feedback: Please send recommendations for improving this guide to the author at email address “ContactFCI” at the domain name “”.

Disclaimer: This paper is provided without warranty. Fosdick Consulting Inc. and the author accept no responsibility for any use of the data contained herein.

Trademarks: All trademarks included in this document are the property of their respective owners.

About the Author: Howard Fosdick is an independent consultant who works hands-on with databases and operating systems. He’s written a couple hundred articles and several books. He’s presented at conferences, founded software users groups, and invented concepts like hype curves and open consulting.

Acknowledgments: Thank you to the reviewers without whose expert feedback this guide could not have been developed: Bill Backs, Huw Collingbourne, Rich Kurtz, Scott Nemec, Priscilla Polk, Janet Rizner, Kate Robinson, and others who prefer anonymity. Thank you also to the Association of PC Users (APCU), Better Software Association, BitWise Magazine, IBM Database Magazine, and UniForum.


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