a friend of mine bought a gateway pc a little over a year ago. he wants to reinstall vista home premium because it has been running like junk lately he does not want to use the disk that came with the pc because it loads up a bunch of bloatware with the install. i have a legit vista home premium full install dvd. can we use his vista home premium key that came with the machine and my disk? or is he stuck because it was an oem installed copy?