My Alienware 17x 64 bit windows 8 runs cod ghosts just fine, then when I come to chapter 7 and repel down the building I kill the first enemy using the command E, but then I need to kill another enemy as he approaches me and I cannot throw the knife, trying every key on my keyboard. I am stuck at this point and cannot of course continue on with the game. Any help would be greatly appreciated. ross reg549@yahoo.com