You could extract original files from the WIM if you still have the installation disc.
I'm sure there's file verification tools out there too.
Could also be a dodgy explorer extension (Autoruns).

But if you're going to reinstall, you won't need to worry about that.

(11/03/2011 01:51 PM)Assassinator Wrote:  Go with x64 either way.  Little reason not to use 64bit these days.

If your comp's old with not too much RAM.  I'd probably say minimum 1.5-2GB if you want Vista/7 x64, or minimum 768MB-1GB for XP64.
But 4GB, go with x64.