I don't have any other ideas? If there is a BIOS recovery procedure and you are going to try it, I'd print out the instructions and follow them to the letter. If you use a USB thumb drive, make sure its formatted correctly. It may have to be formatted in FAT, or FAT32 and not NTFS.
Computer type PC/Desktop System Manufacturer/Model Number Home Built OS Windows 8.1 Pro with Media Center 64 bit CPU AMD Phenom II X4 980 Black Edition Deneb 3.7GHz Motherboard Asus M4N68T-M V2 µATX Motherboard Memory 8GB 4GBx2 Kingston PC10600 DDR3 1333 Memory Graphics Card Zotac NVIDIA Geforce GT640 2 Gig DDR3 PCIe Sound Card VIA VT1708s High Definition Audio 8-channel Onboard Monitor(s) Displays 22" LG E2242 1080p and 2 19" I-INC AG191D Screen Resolution 1280x1024 - 1920x1080 - 1280x1024
Keyboard Logitech Wireless K350 Wave Mouse Logitech Wireless M570 Trackman Wheel PSU Retail Plus 465 Watt Case Power Up Black ATX Mid-Tower Case Cooling Stock heatsink and fan Hard Drives 1 TB WesternDigital SATA-300 Drive Internet Speed 80 Mbps Down 30 Mbps Up Antivirus Windows Defender Browser Internet Explorer 11 Other Info HP DVD1040e Lightscribe - External USB2