When I try to install Sims 3 on my iMac, the game installs to 98% and then the mac shuts off. I had the same trouble with Spore as well. No error message, just turns off. Has anyone else experienced this? In a related note, is there a way to remove things from the registry? When I check under "About this Mac", the game is listed under apps once for each attempted install. Wouldn't mind buying games but am a little gun shy after 2 failed attempts.