YouTube user Andrew Tait has uploaded a video titled "Chain of Fools : Upgrading through every version of windows (HQ)" (via Slashdot). In it, he takes a computer running Windows 1.0 on top of MS DOS 5.0 and upgrades it all the way to Windows 7.

Tait said the whole procedure took him three days, though he estimates that only 12 hours was spent doing the actual installing and the rest of the time was spent trying to obtain valid copies of Windows. He even managed to get the DOS versions of Doom 2 and Monkey Island to run on Windows 7 when he was done. In the 10-minute video, Tait points out changes to system settings and application compatibility as he upgrades each version:

"My parents have had a PC since I was about 5, so I have many nostalgic memories about early versions of MS-DOS and Windows," Tait said in a statement. "This is probably why I chose this project, as it gave me a chance to relive some of those memories, and finally gave me something to do with my cupboard full of old computer software."

It's rather impressive that the upgrading was so successful. I've personally always made a point to do a clean installation when I get a new version of Windows. Have you ever upgraded Windows, and if so, what was your experience?