Try not installing it at all .. copy all files to your hard drive and and go into the directory and run the game .. I am not sure about your version but the game is not compressed and does not require any regestery info that's important.
It should run right from your drive without installing.
It would be right to have a real bought version but i am not going to rage on you and be a two face .. like i have never done something like that before :P