few months ago I've installed Windows 8 and still after many many tries I can't get it to work propertly, couldn't find anywhere on internet same problem.
The thing is every 5-10 minutes my screen goes black for approximately 10 seconds, and GPU fan stops spining.
After that everything is fine :S While using Windows XP or Windows 7 everything is working great.
I tried several versions of Win 8 downloaded from MSDN AA (free for students), but this happen in everyone of them.
Happens without installed any drivers, then I installed MOBO drivers... still happens, installed GPU drivers still happens (but noticed if that black screen happen during install driver will fail to install)