


When done, quit Disk Utility to return to the utilities window.Optional: If you previously used Disk Utility to add internal volumes other than Macintosh HD, you can erase them individually using the same process.If this button isn't shown, click Erase instead. Format: APFS or Mac OS Extended (Journaled), as recommended by Disk Utility.Click the Erase button in the toolbar, then enter the requested details:.Select Macintosh HD in the sidebar of Disk Utility.From the utilities window, select Disk Utility and click Continue.If asked, select a user you know the password for, then enter their administrator password.Start up from macOS Recovery: Turn on your Mac, then immediately press and hold these two keys until you see an Apple logo or other image: Command (⌘) and R.
