Black ops virus?

Hey,
So I've been fooling around with Black Ops for a while, and then I got sick of having to be online or have a disc to play it, so I installed a crack... then my friend informed me that the crack might not be legal,   so I got rid of it, Now, whenever I start up my pc, AVG comes up and says it found 2 trojans, in my appdata directory, one called blackopsp and one called blackopsmp. Also, two windows come up and say they could not start an exe with some random 5 digit code. I went to my directory and found those exes and deleted them, and the ones avg found, but THEY COME BACK EVERY TIME I REBOOT!