Submitted by It’s something lots of people here on OSNews have been waiting for. It’s something we’ve talked about, something we’ve theorised about, and something we’ve declared as the future for Windows’ backwards compatibility – and now it’s here, and official. Over a month ago, Microsoft bloggers Rafael Rivera and Paul Thurrott have been briefed by Microsoft on a technology for Windows 7 called Windows XP Mode. Available as a free download for Windows 7 Professional, Enterprise, and Ultimate users, it’s a fully integrated and licensed copy of Windows XP SP3 in a VirtualPC-based environment, with full “coherence” support. In other words, it’s Microsoft’s variant of Apple’s Classic environment, and it’s coming to Windows 7, for free. Near-instant update: The Windows 7 RC will indeed be available publicly on May 5. TechNet/MSDN will get it April 30.
Windows XP Mode is built on the next-generation Virtual PC 7 product line, and requires processor-based virtualisation support in order to run. It comes with “coherence” support, which means that you can run Windows XP applications as if you were running Windows 7 applications. What all this means is that Windows 7 with XPM delivers full Windows XP application compatibility, a massive advantage Windows 7 will have over Windows Vista, and a major selling point for enterprises still using Windows XP now.
However, it has more far-fetching consequences than that. “Obviously, XPM has huge ramifications for Windows going forward,” Rivera writes, “By removing the onus of legacy application compatibility from the OS, Microsoft can strip away deadwood technology from future versions of Windows at a speedier clip, because customers who need to run older applications can simply do so with XPM.”
I, and literally countless others with me, have been proposing such a solution for ages now, as a means to allow Microsoft to cut the backwards compatibility cruft from the Windows operating system, allowing them to introduce new features and bugfixes at a much faster pace. It seems Microsoft has realised the same thing.
Windows XP Mode will be a completely free download for users of Windows 7 Professional, Enterprise, and Ultimate. It will include a licensed copy of Windows XP SP3, so you don’t have to bring your own.
A very wise and very welcome step by Microsoft. I’m not easily excited, but I am a little bit now. I can’t wait to test this out!
Can it still be infected using classic techniques? If it is a VM then it is a yes.
Also will it get updates beyond xpsp3 end date. I mean will it be supported with security updates for the life of win7. It might be xpsp3 but this is a new product with new packaging.
I’m sure it will run in a sandbox, so you’re pretty safe.
Well, hopefully, patches for the virtual Windows XP will just make their way onto your machine via Windows 7’s update panel. It’d be pretty braindead (but oh-so–typically-Microsoft) if you had to use the virtual XP’s Windows Update.
It might be easy, but it sure will be unsecure.
Of course will all XPM apps have access to your personal files. That is what users want. And MS will do just that. Security does not matter.
VirtualBox gives you the same thing for free on nearly every OS.
Edited 2009-04-25 14:33 UTC
Well, technically, wouldn’t VirtualBox give you the same thing for the price of a Windows XP license (are these still available? what do they cost?)? Or don’t you need a license to use Windows XP if it’s virtual with a Vista host?
Vista is inherently more secure. Windows 7 should be if the pattern is followed correctly. I made sure UAC was _on_ and forced everyone to enter their password for non-trusted binaries.
XPM may run in a sandbox, but it may as well be wiped and reinstalled daily or after each use. We may as well be running a virtual center lightweight host with XP guest. Either way, that guest is _not_ secure just because it runs atop a secure OS. The thought of regressing to an OS capable of failing to stop basic arbitrarily executed code (most malware) from running is not a selling point to me.
Vista is fine and Windows 7 has better UAC flexibility, but this mode is actually crippling. The number of people thinking this is a good move will use it, increasing a demand for continued compatibility for XP, and app makers will not have a need or urgency to step up and fix their apps.
Would it be smug of me to say that anyone who disables security protection such as the UAC or would rather use XP downgrade/XPM after buying their new PC with Vista/Win 7 deserve to have their private data stolen?
– use UAC smartly
– use an os with randomization of code space (like ASLR) – guess which one out of Vista, Win7 and XP doesn’t have this
– die xp
I am so glad that Microsoft finally did this. I heard more than 50% of their code in Windows is legacy stuff. Hopefully, in the near future, they can rip that legacy stuff off and make Windows leaner.
Exactly. Hopefully in the end this will lead to something entirely new, ideally no Registry, no DLL…
A true 21st century OS, with other words.
Umm… Do you know what DLLs are?
Are you saying all Windows software should be statically linked?
http://en.wikipedia.org/wiki/DLL_Hell
http://www.linuxforums.org/forum/coffee-lounge/37811-does-linux-use…
http://www.securityfocus.com/infocus/1872
http://www.securityfocus.com/infocus/1873
Dude, quit trolling. DLL hell hasn’t occurred since forever.
I might as well state that every Linux machine will face dependency hell – and I’d be trolling.
Did you care to read the other links?
Yes I did. Now would you care to explain exactly why you think windows should get rid of dynamically linked libraries? Posting a bunch of links does not a valid argument make.
The irony of Anymous Penguin is the fact that he provided a link ( http://www.linuxforums.org/forum/coffee-lounge/37811-does-linux-use… ) that refuted his stance on the issue of DLL’s and the apparent issues in the form of DLL Hell (which is just as annoying as dependency hell)
So Linux/UNIX has DLL’s already but they’re called share objects, but then the person goes on to say:
So the issue has nothing to do with DLL’s but the lack of versioning of DLL’s; that can be fixed without making an idiot claim of ‘getting rid of DLL’s’.
PS. What I am posting is on the assumption that the the post on that link is correct.
From wikipedia:
…particularly legacy 16-bit editions.
NT mostly did away with those problems along time ago. I’ve never had such problems on Win2k or later. Apparently you haven’t used Windows much since ’98.
The next link talks mostly about the registry (which is garbage, I’ll grant you that). The only real mention of dll hell references the wikipedia article.
The securityfocus.com pages aren’t working for me, so I can’t comment on those, though, if they’re in the same vein as the other links, they probably aren’t very accurate, current, or helpful.
2006-08-08
Is that current enough?
Win7 is looking better and better
I was hoping they’d do this.
MS is becoming quite smarter everyday. I’m personally hoping it’s sandboxed. Although expecting “win8” to feature a whole new api is *still* far-fetched..
I think so too. and it’s after Bill’s departure!
Why we’re skipping Vista altogether and going for Win7 after the first service pack.
You don’t need to wait for a service pack. MS is on the ball with Windows 7 and it is runing really well from Public Beta onwards.
Being testing it with Graphic Design and Audio Duties and it shines. Also is handling the Media entertainment centre well although I am utilising Foobar2000 for audio and VLC for Video.
This is what Vista should have been but then I know OS-X wasn’t so hot on release either.
Pulling legacy code/API’s out of Win 7 and virtualising them is a very smart move on MS’s part but it took Apple and Linux to show MS how easy it could be done.
Remember when OSX 10.0 came out Apple made it pretty clear that is was Beta software and would be a while before this would be good for production. They didn’t try to push people to use it making people think it was great yet by their own admission its half baked.
Apple charged $129 for 10.0 Cheetah but gave Cheetah users a free upgrade to 10.1 Puma. They also gave you a choice between full OS 9 or OS 10 till 10.2 on their PC’s.
I found OSX 10.0 to be much worse than Vista, and that’s why Apple was reluctant to push it as much (I don’t recall them belittling it to the extent you claim; I can’t even imagine Steve Jobs admitting to Apple releasing “half-baked” product). I also found OSX 10.1 to be little more than a service pack for OSX 10.0, so sure, it was free, just as Microsoft’s service packs are.
Vista wasn’t all it should’ve been by a long shot, but there’s no need to pretend that Apple was any better with the way they handled their early OSX releases.
This is great news!
Edited 2009-04-25 02:33 UTC
Indeed! This is bleeding AWESOME!
I work for a small non-profit and we were really worried about having to update to Windows Vista/7 because it is incompatible with our current CRM which we can’t afford to upgrade due to the bad economy. This means we can still buy new computers as our old ones crap out and not have to worry about spending $10,000 for an updated version of what we currently run. I’m running Vista on my home laptop right now (I have an XP/Ubuntu Dual boot server as well) and I think I might actually be tempted to upgrade Vista to 7 once the first Win 7 SP is released.
This is great news!
Sounds good IF you have the hardware for it as always.
Meaning you have to have a VT processor in your PC. If you dont you can’t take advantage of it.
As always, something cool from MS that is just not quite there. 🙁 Too bad so sad for most.
If you read the fabulously friendly article it states:
So you can run it on hardware that doesn’t have hypervisor – it might not run as fast but it’ll work. With that being said, most hardware in the last 3 or so years have some form of hypervisor included.
I wish they would scrap all compatibility (shims and other stuff) in favour of having XPM – where compatibility is provided by the actual operating system it was intended to run on rather than trying to provide a compatibility layer.
Edited 2009-04-25 06:49 UTC
Well if you read outside of the fabulously friendly “Lacking in details” article then you see:
“XPM is built on the next generation Microsoft Virtual PC 7 product line, which requires processor-based virtualization support (Intel and AMD) to be present and enabled on the underlying PC, much like Hyper-V, Microsoft’s server-side virtualization platform. However, XPM is not Hyper-V for the client. It is instead a host-based virtualization solution like Virtual PC; the hardware assistance requirement suggests this will be the logical conclusion of this product line from a technological standpoint. That is, we fully expect future client versions of Windows to include a Hyper-V-based hypervisor.”
That covers most (But not all)
* Intel® Core™2 Quad Processors
* Intel® Core™2 Duo Processors
* Intel® Core™2 Extreme Processors
* Intel® Pentium® D Processors
* Intel® Pentium® Processors Extreme Edition
* New Intel® Pentium® 4 Processors
But that leaves out almost all Mobile M processors, almost all Celeron and Atom processors etc. Basically almost everything on the low end.
Speaking of which XPM will also only be available for Professional, Enterprise, or Ultimate. But Home users are left out.
So as always they have to find a way to get you to spend more. I understand that they are in the business to make money but at the same time they don’t have to nickel and dime people.
Edit:
MS is going to have a hard way to get from under the shadow of XP. I don’t see why people would pay more to get Windows 7 and then run XP apps in a virtual layer when you can just run XP. I don’t see why people would flow with Windows 7 starter when (If companies can get and resell it) companies will sell XP on netbooks and nettops.
Edited 2009-04-25 12:49 UTC
Thank you for the correction; I would have corrected my post (realised the error around 30 minutes after I had posted it – too bad OSNews has this ridiculous 20 minute limit).
According to:
http://en.wikipedia.org/wiki/X86_virtualization#Intel_Virtualizatio…
Some Core and Atom chips have VT. What ever the case maybe most companies are on three years cycles where the depreciate their computers over a 3 year period and keeping them beyond that basically becomes a cost burden. Also, once you upgrade to Core 2, the need to upgrade on the three year cycle will be reduced given that Core 2 pretty much provides all the features that a business would require when it comes to virtualisation, speed, reliability and future proofing.
I’m surprised they just didn’t offer it to all customers and finally remove all the backwards compatibility out of Windows; it would have been a cleaner way of sorting out alot of the problems in Windows – and provide backwards compatibility that can be assured because one is actually running it in a real session of Windows rather than relying on shims which are an attempt to replicate Windows XP but many times fail.
It’ll be interesting how they address that quandary – then again I’ve always maintained that Microsoft needs to move away from their dependence on Windows and Office so that they can pull down the price, have server and desktop edition (and differentiate based on the level of support rather than features) – and put all the focus when it comes to profit on the middleware.
I think the problem with going the middleware direction is that MS can’t lock you in as easy that way. Right now their lock in is Office on Windows. Office on Mac is one of the things that has grown the Mac as of late. People don’t feel so scared to switch. And MS is making money off Office on Mac knowing that Apple will never get but so big in the “PC” market because of their price point.
Middleware from MS will get hammered by Oracle, RedHat and IBM. There is no “Must Need” product made by MS besides Windows and Office.
When you look at:
Exchange
Share point
IIS
SQL server
etc.
All those things can be replaced in an environment (Not to say MS is not making money off them) pretty easy with sometimes better products.
I’ll pick a Linux-based solution to those any day, but you’re completely wrong when you say “…can be replaced in an environment pretty easy…”. The actual cost of converting is almost certainly greater than buying new MS licenses flat out. New/very small businesses which don’t have existing infrastructure are another story, but then they’re not exactly converting, are they?
True. But if you don’t have the Windows tie in then you wouldn’t need any of that Microsoft middleware in the first place.
None of MS’s middleware is best in class. Its the best to tie in to your existing Windows infrastructure most of the time. But you take Windows and Office out of the equation then that tie in goes away.
But you are right once you are trapped into the Windows Twilight Zone there is nooooo getting out! LOL!
What I’m wondering about is whether Windows 9X, Windows 3.X and DOS will be supported eventually? With the possibility of the DOS command line being dropped altogether in favor of the Powershell.
Because I know that in some enterprise environments there is so much legacy code (and legacy hardware such as custom expansion cards) that needs full Windows 9X (and believe it or not Windows 3.x or DOS) support.
This also leads me to wonder who will be the first Linux distribution to make a Linux VM purely for Windows 7?
The only part that bugs me is that a separate license is required for each VM environment, gladly a XP license is included but what about 9.X and 3.x if they make these available? It would be kinda pathetic to ask businesses paying for 7 Professional to plunk down $50 or so for Windows 3.1.
I know! I would personally be excited if it supported old DOS and Windows games. No more necessity to fiddle around with DOSBox.
Can’t something like this be done on Linux? I mean, didn’t Parallels do something like this on Apple? Running Windows apps as if they were OSX programs? Instead of creating a new window and running everything within a window, the programs are stand-alone with XP border (I think) among the OSX ones and shadow effects on their windows. They even appear on the dock. Why can’t the open source community create something like this? You won’t ever need WINE and it will be 100% reliable since it’s virtualized and XP is what actually is running the programs.
Edited 2009-04-25 05:18 UTC
VirtualBox is open source and is the closest thing. You have seamless mode which is close to how VMware and Parallels does it.
The one thing about running in this manner is that you loose several things that you have with Wine. For one printing is always crazy (Same problem you had with Mac Classic mode) Networking can be a problem, and speed is for sure a problem (So you can’t really play games etc)
With Wine if the app runs in Wine then you access a lot more features and also you can run more games etc.
It still requires an XP license as well as the overhead (at least in memory usage) of running an entire extra OS so it does not really replace the Wine project.
VirtualBox does appear to support separate windows. It calls the feature “seamless mode” which has had support for Windows, Linux, and Solaris guests since v1.6.
Seamless mode, hmm I didn’t know that. Thanks. In relation to a separate license, in my own opinion, that shouldn’t be a problem. The VM would assume the user has a copy of XP. (Ultimate Boot CD for Windows)
“It still requires an XP license as well as the overhead (at least in memory usage) of running an entire extra OS so it does not really replace the Wine project.”
The XP license will be included for free with the download so that really isn’t an issue.
Yes, XPM includes an XP license. I meant you need a Windows license for running Windows apps on Linux via virtualization as opposed to Wine which does not require a Windows license (although I believe it works better with some Windows DLLs, so unless/until those are reimplemented, a Windows license helps for Wine). Of course, at the moment, Wine is not an option for some apps.
I think Microsoft is beginning to move forward a bit… only about 7 years late, but hey, they own 90% of the market so why not…
Also because it might get me a fully Managed (Midori) OS to play with on a real PC
.
Personal wishes aside, it should allow MS move forward while making the OS lean and mean.
This is good news
.
i still don´t understand what´s the difference between this and other VM solutions except that there will be extra edition of Win 7 without virtual XP for European Union
remember the IE vs other browsers problem
EDIT: oh it´s not included with the OS installation. stupid me. but will there be free Win XP license for other VM´s on windows 7?
Edited 2009-04-25 08:42 UTC
I dont have Virtualization extentions in my CPUs,
NONE of my CPUs 🙁
And if I had would this work with 3d games ???
Edited 2009-04-25 09:52 UTC
Not likely. Is your game totally incompatible with Vista/7?
Intelligent move.
Now get on with the release of Midori.
Still worse than XP which has a built-in classic environment, that does not suffer from the performance-misbenifit of virtualisation.
XP does however suffer from the misbenefit of being Windows XP.
Edited 2009-04-25 10:40 UTC
I was just thinking to myself that no matter what, Win7 still doesn’t offer any reason whatsoever for me to upgrade from WinXP; WinXP doesn’t take gigabytes of HDD space, it doesn’t require gigabytes of memory to run well, the games I play run a lot better under WinXP..
There were many benchmarks on Windows 7 vs Vista vs XP. Basically if you have a modern machine (4GB RAM, etc), Windows 7 is the OS you’d like to use for the maximum performance.
XP is old, and if your machine is so too (like 5+ years), then you should stay with XP.
I still prefer WindowsXP over WinVista even though I have a quick machine with 8 gigs of ram. I rather run XP with 3 gigs of ram than use Vista with 8. I just had so many bad experiences with it. Most important reason is, that XP still feels a lot snappier and faster.
For example this happened recently:
While running Vista win explorer showed a strange behaviour, i could not click on files, open them etc. Then the machine hung and I needed to reboot. Vista was not able to read the NTFS filesystem anymore. I started Linux and I was able to browse the filesystem and back the important stuff up. I started from Vistas recovery cd and ran chkdsk, this nearly took 4 hours and there was a lot of fixing. Still the MBR was gone and somehow not fixable. Additionally I was not able to mount the drive in linux anymore. I reinstalled Vista on a new drive, but I gave up as the first bluescreen appeared while installing the SP1. Now I’m back to XP and I will stick with it for as long as possible. At least it makes me somewhat independent from microsoft terrible update packages, since only real important updates will show up in the future.
The only way I can see happening what you described is if you had a bad driver, or gave permission to install shady software. Vista doesn’t just crap out like that for no reason. Or, a faulty hard drive. considered that one?
It’s not XP we’re talking about.
Edited 2009-04-25 13:13 UTC
Could have been a driver problem, even though i was using the newest chipset(intel p35)/gfx(nvidia gf8000gt) drivers. The harddrive physically still works, just that i can’t access the ntfs-partition anymore. I didn’t have any spyware/virusses installed.
Thom, I know you find Vista and/or Windows 7 to be the best thing since sliced bread, but it doesn’t always work so well for everyone. Whether it’s a crappy driver or not doesn’t really make a huge difference in the end for the person having the trouble, does it?
And, that being said, some of the drivers included with Vista itself must be extremely buggy–certainly possible, as they’re still developed by the hw manufacturers and MS just includes them in Vista. I had an Intel ICH8-based internal audio chip that repeatedly caused a blue screen in Vista, and that was with the driver included with Vista itself. There are no driver updates for this particular card.
In some situations, the argument over whether it’s Vista or a driver is meaningless. It reminds me of the argument I here from a lot of Linux users that Linux doesn’t crash, Xorg or the desktop environment might crash but the kernel does not. In the end, it’s irrelevant, and all part of the same whole to most people.
Further, how bad must the Microsoft driver certification procedure be if such drivers make it through their screening? With the number of problems Vista can have and if, as you say, Vista doesn’t have problems and only the drivers do… I think Microsoft better bump their driver QA a bit, especially for drivers that are included as part of a default installation.
You can’t blame everything on Vista or Microsoft, but you can’t blame everything on bad drivers either.
You are describing a hard drive failure. Even if it is working now, it is just a matter of time before it dies again. I would highly recommend getting a new one, and until you do back everything up as rigorously as possible.
Not necessarily. I’ve seen similar things happen to NTFS filesystems, although in my case it was in Windows XP. Basically, if you’re unlucky enough to have to reset or power off the system right as NTFS is closing a write to its master file table (mft), it can bring the filesystem down under the right conditions. It can also cause other interesting things if the MFT becomes just a bit corrupted due to this, e.g. used clusters end up being marked as free, causing random disappearances of files and/or folders, or portions of the pbr to be erased.
It could also be a failure on the motherboard, with the IDE or SATA controller crapping out (not sure which connector that drive used), or it could be the Vista motherboard drivers are buggy as hell. It could even be an unlucky power surge just at the wrong time that overloaded the surge protector and fried a portion of the OP’s hard drive, I’ve had that happen once as well. That required a low level format of the disk before it would work properly again, as certain areas had to be zeroed out before they could be written to. This could explain what happened with your mbr, and the blue screen afterwards although that could very well be your motherboard drivers as well.
This is not a clear case of hard drive failure by a long shot.
So let me get this staight, you are basing your assessment of Windows 7 on Windows Vista even though there have been reports after reports, articles after articles showing a dramatic decrease in memory usage, improvement in performance over Windows XP on the same hardware. So rather than looking at facts you resort to lying to justify your decision – interesting to see that honesty is a rare commodity on this forum.
Give Windows 7 a try on May 5th. AFAIK, it runs as well as XP – an Atom-powered eeePC is one of Sinofsky’s testing machines. It runs great even on a VM, something I can’t say about Vista
Is there a VM Aero works on?
Nope. VirtualBox may be able to in the future, since they already support Compiz.
This is simply the next version of Virtual PC which adds native host OS integration (removes the desktop and start menu/taskbar from the guest OS). This should in an ideal scenario work with any OS, esp Vista, but Microsoft is trying to sell if off as an exclusive Windows 7 feature for business reasons. VMWare Workstation 6.5 released in September 2008 aleady does this (called Unity mode instead of XP Mode) and isn’t locked for Windows 7 hosts and Windows XP guests. Sadly, THIS WON’T GIVE ME BACK THE FEATURES REMOVED FROM WINDOWS VISTA OR WINDOWS 7 WITH NATIVE INTEGRATION. Users will still have to manage and patch this “Virtual XP”. This won’t take management of the XP VM (patching, defragmenting) out of the equation.
VMware doesn’t come with an XP license. It also isn’t free (unless you pirate it).
I’d be surprised if Microsoft made you patch XPM separately. As for defragmenting, well, that depends on their implementation. I expect you won’t have to manage a seperate virtual disk, that user files and XP apps will be stored on the host filesystem. That wouldn’t be to difficult to accomplish. That would also put file system management in one location.
vmware server is free. So is vmware player
If XPM is a virtual XP, whether you patch automatically through a central tool or not, you will still have twice the patch downloads. One download for Win7 and the other for XP.
A virtual machine requires a method of booting its own filesystem and this is accomplished through raw devices, partitions or pseudo drives created from one big disk image.
Also, I’d rather the XPM not be able to put its library of malware on the host OS filesystem.
What I’d love to see is for Microsoft to provide a free vanilla Windows XP Virtual PC image that allows an end user to put their old Windows XP OEM serial number in it and thus retain the benefits of Windows XP which came with their machine. After all, they did pay for the software – why shouldn’t they be allowed to use it within a virtualised computer to make migration to Windows 7 easier?
This is a great move on Microsoft’s part. It shows that they do listen to their users.
As for those who slight Microsoft for now allowing XPM to run on systems without hardware virtualization, well, you should learn about a thing before you talk about a thing. There are technical reasons why that’s the way to go, and business reasons not to.
Hardware virtualization offers a measure of security and stability that isn’t possible with a purely software approach. If your processor supports nested page tables, which the newer ones do, you get a performance boost, but if not, well, you still get the stability.
The idea that they are trying to force you to upgrade your computer is unfounded. They are not in the hardware business. Most new systems (except the low-cost low-performance systems) support hardware virtualization. By not requiring virtualization support, they have a wider audience to sell to. However, they decided to listen to the technology and not the marketing. They should be applauded.
Let’s not forget that the purpose of Windows 7 isn’t to fix the Vista technology, it’s to fix the Vista stigma. Now that SP1 is out, now that the hardware has come around, Vista turned into a fine piece of software (once you turn UAC off, that is). However, it is still treated extremely unfairly by the media.
The last two operating systems from Microsoft have added a little security, while stripping the user of their last rights. Windows 7 and Vista are upgrades–DRM upgrades.
You’re being overly dramatic and more than a little asinine. How are Vista/7 “stripping user of their last rights”? Their last rights to what exactly? You do know that both Vista and 7 themselves have been massively pirated and that they feature the same activation crap that XP has, right?
If you’re really just complaining about WMP, then just admit it and switch to MPC or VLC like everyone else.
…on the street.
So how much will they slug home users so they can keep using the apps they paid inflated prices for?
Can’t Windows 7 run XP applications? Vista runs XP applications quite perfectly.
And everyone is terribly excited about this crutch. It seems to be very easy for MS to get people excited about all sorts of crap. Oh well …
I suspect that Red Hat might be interested in this kind of strategy for their RHEL product. It would add an extra level of confidence for their customers when they upgrade.
In fact, I have a situation right now where I had to *add* an old CentOS 4.x server to run a C/ISAM <-> SQL gateway. We upgraded the old server to 5.x, and everything else was fine… except for this, admittedly clunky, but absolutely key, piece. I might have done things differently if Centos 4.x had been virtualized into CentOS 5.x out of the box.
Just because MS does something does not mean that that something is necessarily a bad idea.
VM still require substantial memory usage as well as HD space. Not to mention the need to set up each VM configuration
It maybe a better solution to run XP apps over an XP terminal server such as ThinServer XP
http://www.aikotech.com/thinserver.htm
Does anyone have any info on what version of XP will run in the VM? Will this be a 32-bit copy of XP, even if the Windows 7 host system is 64-bit? If this is the case, the VM’s main purpose IMHO is to allow for 16-bit compatibility (and apps that require NTVDM to run). Windows 7 already has the ability to run the 32-bit code itself.
I dont agree with this solution for achieving backwards compatibility. In my opinion it is a really bad solution. Why is is bad? It doesnt scale. It is no long term solution, the problem of achieving good backwards compatibility persist.
In Windows 10, will there be a virtual machine for WinXP, Vista, Win7, Win8 and Win9? Imagine how much RAM and CPU and disk space all these virtualized Operating systems will require. The fact that there is WinXP virtualized inside Win7 is a testimony MS can not get Win7 backwards compatibile. They have to cheat by inserting a whole WinXP inside Win7. That is a BAD thing. Always, new versions of Windows breaks compatiility; Vista breaks WinXP, WinXP breaks Win2000, etc. MS is very bad at backwards compatibility, as evidenced by Word2003 inability to create Word97 files, it is black magic to MS too!
http://lists.kde.org/?l=koffice&m=101502075222664&w=2
In my opinion, the best solution is to keep backwards compatibility and still develop the OS. It can be done: SUN _guarantees_ binary backwards compatibility back to Solaris v2.6. And now Solaris is v5.10. And the development of Solaris is amazing; ZFS, DTrace, Zones, etc. This way you keep the OS slim and clean and efficient.