Hi everyone, longtime reader here, first time poster. I have a question concerning the $30 dollar Snow Leopard upgrade disc. I recently recieved a 20" iMac from a friend, with Snow Leopard already installed but he didn't have the install discs that came with it. My question is, if I were to buy the Snow Leopard upgrade disc, can I perform a clean install of Snow Leopard? Even though it's an upgrade disc? Thanks!