how to do a clean install of mac os sierra

Otherwise you're offered the macOS that came with your Mac, or the closest version still available.

If you use Option-Command-R during startup, in most cases you're offered the latest macOS that is compatible with your Mac. On an Intel-based Mac, if you use Shift-Option-Command-R during startup, you're offered the macOS that came with your Mac, or the closest version still available.When you install macOS from Recovery, you get the current version of the most recently installed macOS, with some exceptions: When the new owner starts up the Mac, they can use their own information to complete setup. If you're selling, trading in, or giving away your Mac, press Command-Q to quit the assistant without completing setup. Your Mac might restart and show a progress bar several times, and the screen might be empty for minutes at a time.Īfter installation is complete, your Mac might restart to a setup assistant.

Allow installation to complete without putting your Mac to sleep or closing its lid.If the installer offers you the choice between installing on Macintosh HD or Macintosh HD - Data, choose Macintosh HD.If the installer doesn't see your disk, or it says that it can't install on your computer or volume, you might need to erase your disk first.If the installer asks to unlock your disk, enter the password you use to log in to your Mac.Select Reinstall macOS from the utilities window in macOS Recovery, then click Continue and follow the onscreen instructions.įollow these guidelines during installation:

How to do a clean install of mac os sierra