Say I have Widows Vista, and want to purchase a Windows 7 upgrade. The upgrade is cheaper, but the down side is that I have to the install that will transfer files and programs. I DON'T want to do this, because I want to format and clean the hard drive for a new start. But again, the upgrade is cheaper. When you put the upgrade disk in, will it let me choose between a clean full install or an integrated install? I sure hope so. I also heard you can buy the upgrade and use it for XP, but you will have to do a clean install, which means it might be possible on Vista.