I was having trouble on my M3A770DE board because Windows 8 had turned on that UEFI thing so I could no longer access normal BIOS. I tried everything to turn it off or to access bios screen in windows 8 (which it doesn't have with my board). It took a little while but then I realized the sort of FIX. Update your bios using the windows bios update tool. It wipes everything on the bios including the UEFI crap and puts the BIOS back to original form. I'm thinking this is probably a last resort sort of option since you probably don't want to be messing with the bios tool very often, but it did work for me. :)