Windows XP

I know this sounds retarded but I downloaded a copy of WinXP and I can't find it to install. Help!

 

One way to find where you put it (if you accepted the default location) is to start the download again. Just go as far as where it tells you where it is going to put it, then cancel out of it.
Another way is to do a search in Windows Explorer and look for files/folders created/modified on the day you did the download. Also set a large minimum size for the search - say 300 MB to further restrict search items identified.
Some downloadds go to your Desktop - have you looked there?

 

I am going to assume this is an MSDN copy, as we do not condone, or support pirated copies of software here.