Hey i just downloaded Mw2 the full game. put a crack in for steam. i press play. then it says IWNET INVAILD VERSION. Any fix???

And i tryed alterIwn or w.e server b4 but i could never get it working. like i double clicked the game and it wouldnt open. and i went to there site. to ask for help. and wow there no help at all. but oh well. thats not my problem.

I would like to play on steam i heard zero gear works? if it does tell me and post a tut maybe??