There is one other very important thing you should know. When you have an authorized computer you must remember to de-authorize it before you erase it or sell it. Because you are only allowed a certain number of authorized computers to listen to your music. If you loose a computer or an OS X installation that you did not de-authorize first, you have permanently lost one of your authorized systems. I'm not entirely sure, but I think you are only allowed to have five. The moral of the story is always de-authorize first!