You can find a longish discussion about this in the Computer Help forum but the bottom line is that this is something that Windows doesn't do. If you pop the Restore CD in, it may offer such a item but there is not a feature to "remove my stuff."

Just so you know I'm not kidding, look at this link (it's scary.)
http://forums.cnet.com/5208-6132_102-0.html?forumID=32&threadID=119247&start=0

It's one of those areas when Windows keeps things that could surprise you.

Bob