any copy of windows home will work with your licence number (providing you have the number stuck to the side of your case still) personally this is a case where I would find someone who can get you a copy of the disk (must be XP Home) and go ahead and use that. you paid for it already so you're not really breaking any laws (at least less than microsoft is).
wish I was more help, but I havn't gotten that far into my text book yet.