The problem lies in CD protections, which, sadly enough, know when you are using an iso so won't let you run the game or program. Although you can get a no-CD crack or patch. These sites should have some (I highly suggest you use mozilla firefox to make sure that your computer doesn't get overloaded with spyware).
www.gameburnworld.com they are listed as fixes.
www.gamecopyworld.com
www.cracks.am
www.keygen.us

another suggestion would be to grab the original exe and throw it into an extra folder (like orig exe or something) then throw the cracked exe into the original destination.