Hi, I'm going to be selling my iMac in the next few days (hopefully) and obviously I need to wipe it completely clean. It has OSX Lion on it and I'm not sure how to format the hard drive. Also, when I do format it, will it still have Lion on it when the next person gets it? It had Leopard on it when I bought it, and I upgraded to Snow Leopard and then Lion, but because I paid for Lion from the App Store with my account details, can the next person still use it? Or shall I just put Snow Leopard back onto it? Thanks.