I had wondows 7 ultimate running on my internet machine for 2 weeks. Almosi every day 3 or 4 times a day i would get a completely blank dislplay and then the machine would shut down. There were no critical errors that i could find.
So i installed Ubuntu 12.04 on the same machine with no changes at all. Ubuntu 12.04 is very resource intensive. After 48 hours of running not one crash , blank screen, or any other major problem.
I had the same windows 7 problem on my self built and the dell gx280 i had it installed on. Same problem completely different machines.
I do not think i will be going back to windows , as the experience stated above explains windows 7 is still in need of a lot of development work. When i ran win95 second edition was the last time i have experiences with windows like i have had with windows 7.
Good luck with all you folks that can get it running properly.