I've gotten dozens of emails about this, sorry for not posting it sooner: A blogger by the name of "Andy" has recorded his experiences upgrading from an early version of DOS through every major version of Windows (except Millennium edition for some reason). It's pointless, and his final "complaint" is bizarre, but it's still quite interesting.
See the video, which elapses in under 10 minutes, but took three full days to record.
The whole procedure took 3 days, of which approximately 12 hours was spent doing the actual installing - the rest of the time was spent trying to obtain valid copies of windows.
Another hurdle that had to be overcome was one of system requirements. MS-DOS uses the FAT16 filesystem, which only supports partitions up to 2GB in size. This was no problem until Windows XP, which required a comparatively large amount of space - at this point, the filesystem was converted to FAT32.
I was pleasantly surprised to see the DOS versions of Doom 2 and Monkey Island still running in Windows 7 after all these years. Microsoft has had a lot of stick through the years (not least from me) but this really is a laudable achievement.