Am I able to perform a reformat and clean install of Windows 7 home premium with a Windows 7 Upgrade version? I have a copy of both WinXP and Vista. Way back when WinXP came out, I was able to do a clean install with the WinXP upgrade. During the install process, I simply had to insert my Win98 disk to show that I had a legitimate copy of a prior Windows OS. Will the Windows 7 Upgrade version do the same, allowing me to perform a clean install?