I have Vista Home Premium 64bit fullversion. I was going to purchase a Windows 7 Home Premium Upgrade to do a clean install, but my sister told me she had already pre-ordered Windows 7 Professional Upgrade for her Home Premium 32bit laptop. I was wondering if I could use the Windows 7 Professional Upgrade to do a clean install for MY system. I searched on the forum and could not find an answer, but, would this be possible? Can I use my Vista product key for an upgrade to Windows 7.. or is activation not possible and I should buy an Upgrade disk for myself? Thanks for any help, and sorry if what I'm asking is confusing.