Let me make this as short as possible. I acquired an old sony laptop with XP on it. The backup copy was on the hard drive. After reinstalling XP the pc did not work. Rather than fight with it I took out a disc I had from an old retired pc of mine and loaded that windows onto the laptop.. This was a Dell disc that I own that has Vista.. (all my documentation was tossed years ago) The laptop is running great. I have 14 days to activate and no number. I tried all sorts of things online from key finders to even number that were published with no luck. I called microsoft and they are happy to take $45 to activate it.. I have owned at least 8 computers all with bought windows along with this disc I used... but now I don't know what to do. Buy a new copy off ebay.. and even if I were to do that would I still need to install that copy wiping out all I have done on this pc to date ?