I need to format my computer, but I dont have my windows XP cd. (dont know if I have one in general anyways but apart from that...) Is it possible to find out my registration details or serial number etc so that I can find format my computer, install windows with someone elses cd, use the same serial number and any information as before. I know that there is a kind of activation for Windows XP, will that mean that I cant use my same serial number? Or how does it work? Really dont want to have to go buy a new Windows XP Cd.