I have a brand new Macbook and I recently got a couple of used Macintosh games (Doom II and Myst) but they are not allowing me to play. My computer recognizes that there is a cd-rom in the drive but it has disabled all of the clickable icons for instalation and running the game. Is this because the games are too old for my computer? Or because they were already installed on someone elses computer? Does anyone know if there is something i can do about this problem? Desparate to shoot hell-beast aliens.