MBP with windows 7, wife lost the password to access the MBP and since this is pretty much new just want to re-install windows 7 and overwrite the current info. I know all will be lost which I am ok with but when I restart with the windows 7 install disk in the computer it just goes to the password screen to access the desktop. How do I get it to load from the disk so I can reinstall windows 7?