How to Restore Startup Disk Mac?

Verify and Repair Startup Disk on OS X

Restart your Mac, and press Command + R, while its restarting. Select Disk Utility from the macOS Utilities menu. Once Disk Utility has loaded, choose the disk you wish to repair the default name for your system partition is generally "Macintosh HD", and choose Repair Disk.

How do I Reinstall my Mac Startup Disk?

Restart your Mac.
As your computer is restarting, hold down the Command + R keys.
When you are in recovery mode , click Reinstall macOS and then click continue.
When the installer window pops up, click Continue.

Why Can't I Find Startup Disk on my Mac?

If you cant see your startup drive, open Disk Utility from the macOS Utilities window. Click on your startup drive and click the First Aid tab. Click Run. If the repair fails or you cant see your startup disk in Disk Utilities, youll need to erase the disk and reinstall macOS.

How do I Restore my Mac Without a Startup Disk?

Shut down your Mac.
Hold down CommandOption/AltR and press the Power button.
Hold down those keys until you a spinning globe and the message "Starting Internet Recovery.
The message will be replaced with a progress bar.

How do I Restore Disk Utility on a Mac?

In the Disk Utility app on your Mac, choose View > Show All Devices.
In the sidebar, select the volume you want to restore, then click the Restore button .
Click the Restore pop-up menu, then choose the volume you want to copy.
Click Restore, then click Done.