Ever find yourself locked out of an Apple with OS X? Or perhaps you bought a used MacBook Pro from a dude on the street and don't know the login information. Either way, here's a quick way to get yourself back in:

  • Reboot
  • Hold Command key icon (Command)-S when you hear the chime
  • At the root prompt (#) enter the following:
mount -uw /
rm /var/db/.AppleSetupDone
reboot

After rebooting, you will find yourself back at the new installation setup wizard. Follow the prompts to register the system and create a new administrator account. When you log in to your new account, you may use it to reset the old account's password or delete either account.