If you had asked me, I would have guessed that this wouldn’t be possible. One intrepid OS explorer has made a video wherein he not only installs every version of Windows since 1985’s Windows 1.0, but proceeds to upgrade from one to another. The video, titled Chain of Fools: an Exploration of Windows upgrade procedures, shows how DOS and Windows are installed in a VMWare VM, and how a couple of DOS games were installed to see how newer versions of Windows handle backward compatibility. Similarly, various customizations were made to the Windows preferences to see how they survived the upgrades. Video embedded after the break.
It was interesting to find all the legacy cruft lying around the hard drive even after the Windows 7 install that left fingerprints of previous Windows versions.