If I thought it would make a difference then I'd try Win 7 but this motherboard is certified for Win 8 so I am pretty sure this is not the problem.
I use Windows 8 because the Win 7 64 bit keyboard bug was causing my keyboard and mouse to freeze for 10 seconds every 2 minutes, even in safe mode, so it is a Win 7 problem. To escape Win 7 I decided accept the almost unacceptable and go for Win 8. The lesser of two problems, incredibly. Actually, I may load Linux into VMWare and just use Win 8 mainly as a guest OS, though I will need Windows from time to time for my work.