Short and simple, I bought COD4 to use with my last laptop, after it got installed I think I threw away the box and case(stupid I know), but now that I tried to install it on my macbook, I can't because I don't have a cd key. My last laptop is gone so I can't use one of those programs to find a cd key. Is there anything I can do(legal, I don't want to pirate a copy) to install it? 