I have a 13'' MBP with Leopard (10.5) and my sister just bought a white macbook. With it, comes the installation DVD for Snow Leopard (10.6) I was wondering if I could use and install Snow Leopard with that CD on my computer. If yes, will there be any problems in my MBP? Will any of my info and apps get lost? And, will my sister be able to use that cd later? Thanks for your help!