I'm trying to help a friend, he has a pc (packard bell) which he's had since new, it's an old P4 2.0gb with a 40gb hard drive (so you know how old it is lol). Anyway, he's asked me to reinstall windows on it but he doesn't have the disk, the COA sticker is on the side of the computer for XP home with the product key but this doesn't work with my version of XP home, would i be able to telephone microsoft re: this and have them re-register it for me (him)?