I'm going to use windows vista with bootcamp on my macbook pro, and I've got a disc of windows vista, but I may or may not have a product key to use with it. My question is: should I hold off on installing until I know for sure, or should I just go with it? My concern is whether it'd be easy or hard to get rid of vista if I don't have a product key. (In which case, i'd probably just buy windows 7)