Ok, as i am going from cracked software to legit, i want to completely reinstall my OS (Snow leopard) to make sure any registration files for programs and absolutely everything is gone. Now ive never done this before on a Mac so im just asking id there anything i need to do to ensure that everything is lost in the reinstall? Basically, i want it to be like a brand new Computer again with nothing left behind. Also, will i need any license keys for the OS? Happy Christmas!!