Corrupt Bios?

I have a dell laptop and when i press F2 to boot into the bios it looks likes its corrupt. The laptop does boot into windows and displays everything fine and when i press F12 to chose boot priority it displays fine, this problem only happens when I try to boot into the bios.

I tried flashing the bios in windows with a 1545_A14.EXE bios update i downloaded form the dell website, my computer restarted like it said it would but the bios still had the same problem. I created a bootable dos usb stick and tried to update the bios, it looked like it was successfully  but it still has the problem. I disconnected all power and removed the button cell and held the power button in for 10 secs but that didn't work.

Does anyone have anything else I can try or do you think its a faulty motherboard?

All help greatly appreciated!