My friend was having problems with Windows 7 (Some sectors of his hard drive went bad, and no matter how much I urge him he doesn't get a new hard drive). Now that Windows 8 is out I was wondering how if we needed to have him purchase the system builder or the upgrade. I am wondering this because his computer doesn't have Windows 7 on it anymore so I don't know if the upgrade version would reject his computer, or if it would work. Thanks for all of the replies!