You do this by turning on the computer and pressing the Option, Command, P and R keys simultaneously as soon as you turn on the computer. Make sure that Automatic Login is set to Off. Choose Login Options to bring up the options for logging in.If prompted, enter your password for the account. You will need to toggle the lock icon on the bottom left of the screen to be able to make changes.Open System Preferences on your Mac and then go to Users & Groups.Computer Parts options - 11 groups of items - 40 total selectionsĮlectronics options - 12 groups of items - 56 total selectionsĪccessories options - 10 groups of items - 50 total selectionsĭescription: This article will show you the steps you can take to perform a clean boot on a Mac computer.