I tried using both winsxslite as well as this method by aviv00 to change a win7x64 install. (I dd this in an attempt to fix the 800+MB of file size that is added to my drive after installing 30 or so small windows updates.) for aviv00's, the program (whereisit) wasn't allowed to delete any of the files, even though I gave the command prompt commands and they executed successfully. for winsxslite, phase 1 didn't seem to work (kept saying "could not find file "c:\""), and while phase 2 scan seemed to work (it said it would change 800-900MB of stuff I think), it was let with some files that couldn't be reverted, and couldn't be replaced. If a reschedule was executed, then absolutely everything fubars up (almost no executable file will run in windows anymore). Even ignoring the few files it left stuck, the windows directory wasn't any smaller after the change. In fact, it was actually a bit larger. I am aware that these are both rather old, but have not heard of alternatives. I thought I'd let people know that this didn't work for me, and very likely wouldn't work for you (unless something is pointed out that i should do different of course).