I've searched and seen that Disk Utility is the one I need to use. But this is my situation. I bought this MBP last week of December 2010. Since I've bought it I have not saved any files but some few pictures that are on the internet anyhow. So I could care less about those pictures. The only thing I have done, is saved passwords to forums and logged into bank accounts and stuff like that when on the internet. No files have been saved that are pesonal on the HD other then some applications like caffeine. Can I just use a program like CCleaner since I haven't really done anything on the MBP? Or should I use the Disk Utility option. I plan on selling it today. Thanks!