So, here is the question. I have a valid install of Windows 7 Professional along with my activation code. I downloaded 7 from the MS web site. My wife just bought a copy of Windows 7 Home premium upgrade. The package included 2 disks, one for 32 bit and the other in 64 bit. My understanding is that Microsoft wrote Windows 7 so that the code entered during install is what determines what version of Windows 7 you would end up with. Now here is the question. I usually do a clean install when things go really bonkers. if I need to reinstall Windows 7 Professional 64 bit for some reason, can I use the Windows 7 Home Premium upgrade disk to do a fresh install without having to install XP or Vista first? I obviously don't want to install anything more than I absolutely have to.