Troubleshooting OS update and installation issues on Macs
1. OS cannot be reinstalled on erased macOS devices
OS cannot be installed back on macOS devices after a device wipe.
You may have to install or reinstall the same OS version from scratch to resolve this issue.
Step 1: Boot to the Recovery HD
Restart the Mac, and after the chime, long-press the command + R keys until the menu screen appears. Else, long-press the option key until the boot manager screen appears. Then, choose Recovery HD and click on the corresponding arrow button.
Step 2: Erase the Hard Drive
- Select Disk Utility in the macOS Utilities window and click Continue.
- Select the startup volume (generally Macintosh HD) from the Disk Utility left panel. Then click on Erase in the main window.
- Input a partition name and set the partition format as Mac OS Extended (Journaled).
- Click on Erase in the pop-up window.
- Close the Disk Utility window and go back to the macOS Utilities menu.
Step 3: Reinstall macOS
On the macOS Utilities window, choose Reinstall macOS and proceed with the installation.