I suggest that you (1) clear CMOS (by disconnecting power and unplugging battery from board for 15 mintues) and (2) reinstall the latest BIOS using the Recovery Method. After updating BIOS this way, go into BIOS Setup (Visual BIOS) and reset the configuration using the F9 key. Then, only change those few options absolutely necessary for your hardware configuration (i.e. Boot Order, Boot Mode, etc.).
Hope this helps,