I purchased a new PC loaded with Vista just before Windows 7 came out. I have a program that did not work very well with Vista but I discovered that it worked well with 7 so I purchased a unopened Windows 7 Ultimate complete with COA and key and did a fresh install on my machine. The Operating system worked well for about 4 months and then started showing as non-genuine. I was able to get in touch with the seller and he made some vague excuse that something must be corrupt and replaced it with another sealed copy. After about another 4 months this copy also became non genuine. I contacted Microsoft support and they informed me that the copy of 7 I had was a training copy which only works for about 4 months and then the key is blocked. I could find nothing on the package to indicate this and of course the seller has become incommunicado. My copy of windows 7 ultimate still runs OK except for the non-genuine nag. My question is would I be able to install a Windows 7 Professional over the installed non-genuine Ultimate or would I have to reinstall the genuine Vista before I am able to upgrade to Windows 7 professional.. I am trying to make my machine genuine without paying out big bikkies.