There's only two things I can think of, and it's a combination of both. First, I've had problems with Gigabyte in the past. All sorts of strange issues, sometimes undefinable. Which is why I try to avoid this brand now all together. It seems Gigabyte boards sometimes really don't like certain hardware. I've never been able to find out why though... I try to use Asus now when I can, and maybe my next board will be Supermicro. Stability is more important to me than raw speed. The second thing that comes to mind is that maybe Windows automatically installed some update your motherboard doesn't agree with. Which could be why everything worked OK up to a few months ago and a clean install (with all the most recent updates no doubt) didn't fix it. I'm sorry I can't be more precise, but this is what my gut feeling is telling me.