Start up your Mac from macOS Recovery.
You’ll need to know if your Mac has Apple Silicon, this chip is in models released from 2020. You can view a list of Macs with Apple Silicon here.
For Apple Silicon models, turn on your device and press and hold the power button until the startup options window appears. This should include a gear icon ‘Options’. Select this icon and press continue.
For all other models, make sure you are connected to the internet. Turn on your Mac and press and hold Command (⌘) – R immediately until an Apple Logo appears on the screen.
If you are asked to login, enter your username and password.
From MacOS recovery select “Reinstall macOS” from the utilities window.
During the installation:
- Keep your Mac screen open and do not put the device to sleep throughout the installation process. The mac may restart and display a blank screen & progress bars temporarily, this is normal. Don’t press or try to change anything during this process.
- If you are asked to enter your password, then do so, press enter and let the Mac continue to reinstall.
- If the installer cannot find the disk, or cannot install macOS on the computer, you may have to erase the disk first.
- If you are offered the choice between ‘Macintosh HD’ and ‘Macintosh HD – Data’, choose ‘Macintosh HD’.
If you don’t feel confident completing these steps or you’re still having problems, you can book your device in for a repair and it will be assessed by Apple certified technicians.