We can say for sure that our own Windows 7 upgrade experience didn't take, oh say, a whole day, but according to Microsoft, your own just might. The boys and girls in Redmond set out with a goal of seeing the Vista to Windows 7 upgrade accomplished around five percent faster than an upgrade to Vista, and while it seems that they succeeded, the staggeringly wide range in install times has us a wee bit concerned. A variety of testing situations were put in place, and nearly every profile was tested on low-, mid- and high-end hardware. A clean install of Windows 7 on mid-to-high-end hardware took just a half-hour, but a 32-bit upgrade on a mid-range machine with 650GB of data and 40 applications took an astounding 1,220 minutes, or just under 21 hours. The wild part here is that it's not all that uncommon for a power user / all-around nerd to have a half-terabyte of information and two score programs, and in anticipation of one install actually taking over a day, the team didn't even bother testing this path on a low-end rig. Good thing our imaginations are in check, huh?

http://www.engadget.com/2009/09/12/u...-just-in-case/