

When you've finished, close Disk Utility to return to the utilities window.

Optional: if you used Disk Utility previously to add internal volumes other than Macintosh HD, you can erase them individually using the same process.If you can't see this button, 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 and enter their administrator password.Start up from macOS Recovery: turn on your Mac, then press and hold Command (⌘) and R immediately until you see an Apple logo or other image.
