Hello, i am trying to reinstall windows Xp home edition onto my brothers computer but it keeps saying the Cd key is invalid?. I am using the CD key that is on the legit sticker on the side of his tower ( iv double and re-doubled) that iv typed it correctly with no use. I dont know if this matter but im using my Dad's Home edition CD with my brothers code. Reading some of the posts could it be that my dads CD is a original release CD ( from years ago) and the CD key is recent? if so is there a fix ?