There are several reasons why you might want to format the hard drive from your Mac. Either you want to get rid of the data or you get an error
How to format the hard disk of your Mac
When you format your Mac, you need to reinstall the operating system afterwards. Also, your Mac must be turned off if you want to format it. After shutting it down, do the following:
- Shut down your Mac. Meanwhile, press and hold the “R”, “Select” and “Command” keys simultaneously.
- You can release the corresponding keys as soon as the Apple emblem appears on your display. The mac-OS utility will then appear. Now open the hard disk diagram.
- After that, go to “The disk utility to erase your mounted volume”. Select the “Mac OS Extended (Journaled)” format. Then quit the application.
- To set up the pre-installed operating system again click “Reinstall macOS” in your utilities.
- Finally, restart your Mac.