Hi, On the Apple website the Tutorial for Restoring a Mac to Factory settings says that i should go to disk utility and erase the 'Macintosh HD' first before i put the Snow leopard CD in to reinstall it. What would happen if i did not erase the HD first? and i just went straight in the reinstall it with the CD with all my data still on my Mac? Would it still restore it as new as it would of if i would have erased the HD? Thanks, i know it's a little petty thing but i just want to know the answer.