I use a Logitech unifing connector plugged into the USB2 slot right above the laptop USB port. It lets my wireless keyboard and mouse get into and set the BIOS. I would try another port on the back of the computer and if that does not work try a different keyboard.
OS: Windows 8
CPU: I-7 3770k
Cooling: NZXT Kraken X40
GPU: evga Titan Superclocked Signature
Motherboard: Asus Maximus V Extreme (BIOS 1707)
Memory: Corsair Veneance 16GB (2x8GB) DDR3 1866 (Timing 9-10-9-27)
Sound Card: built on motherboard or Logitech g930
PSU: Corsair AX1200i
Case: Rosewill THOR V2