i have far cry 2, would like to play it, but it says ive used all of my activations when ive only installed it on 2 computers. i would like to know how o get them back. without using the 2 other computers. also ive searched for over an hour and the serial key FC2-7KCT-REMOVED keeps popping up along with 3DA5N-JSU9E-REMOVED. how do i use these?