Is there a way to install a single retail copy of XP (Home or Pro) onto more than 1 computer? I know there's a file that you can copy back into the System32 folder if you're reinstalling, but I'm not sure if that'll work. I had heard that after 120 days, the keys Microsoft gives you over the phone to activate Windows will reset, allowing you to use them again, but I don't want to wait if I don't have to.