At this point you need to wipe the drive and re-install your OS from an external OS installer drive.
First backup anything important off your drive (TimeMachine)
Next create a bootable OS installer using another Mac system, I personally would stick with Mojave for now as Catalina is still a bit buggy! In any case here’s how to create both:
* [https://www.macworld.com/article/3284378/how-to-create-a-bootable-macos-mojave-installer-drive.html|How to create a bootable macOS Mojave installer drive]
* [https://www.macworld.com/article/3442597/how-to-create-a-bootable-macos-catalina-installer-drive.html|How to create a bootable macOS Catalina installer drive]
Restart your system then using the '''Option''' key to enter into the Startup Manager select the USB-C installer drive. Once started go to the menu and select Disk Utility and then delete all of the partitions, then reformat the drive as one GUID APFS partition.
Now exit Disk Utility and start the OS installer letting it do its thing! Your system will reboot a few times and the screen will also go dark so don’t panic!!
In a few hours your system should have finished the OS install. Now before doing anything else apply all of the needed updates. Again, your system will reboot as Apple has updated the system firmware a few times depending which macOS you are installing.
At this point you need to wipe the drive and re-install your OS from an external OS installer drive.
First backup anything important off your drive (TimeMachine)
Next create a bootable OS installer using another Mac system, I personally would stick with Mojave for now as Catalina is still a bit buggy! In any case here’s how to create both:
* [https://www.macworld.com/article/3284378/how-to-create-a-bootable-macos-mojave-installer-drive.html|How to create a bootable macOS Mojave installer drive]
* [https://www.macworld.com/article/3442597/how-to-create-a-bootable-macos-catalina-installer-drive.html|How to create a bootable macOS Catalina installer drive]
-
Restart your system then using the Option key to enter into the Startup Manager select the USB-C installer drive. Once started go to the menu and select Disk Utility and then delete all of the partitions, then reformat the drive as one GUID APFS partition.
+
Restart your system then using the '''Option''' key to enter into the Startup Manager select the USB-C installer drive. Once started go to the menu and select Disk Utility and then delete all of the partitions, then reformat the drive as one GUID APFS partition.
Now exit Disk Utility and start the OS installer letting it do its thing! Your system will reboot a few times and the screen will also go dark so don’t panic!!
In a few hours your system should have finished the OS install. Now before doing anything else apply all of the needed updates. Again, your system will reboot as Apple has updated the system firmware a few times depending which macOS you are installing.
At this point you need to wipe the drive and re-install your OS from an external OS installer drive.
First backup anything important off your drive (TimeMachine)
Next create a bootable OS installer using another Mac system, I personally would stick with Mojave for now as Catalina is still a bit buggy! In any case here’s how to create both:
* [https://www.macworld.com/article/3284378/how-to-create-a-bootable-macos-mojave-installer-drive.html|How to create a bootable macOS Mojave installer drive]
* [https://www.macworld.com/article/3442597/how-to-create-a-bootable-macos-catalina-installer-drive.html|How to create a bootable macOS Catalina installer drive]
-
Restart your system then using the Option key to enter into the Startup Manager select the USB-C installer drive. Once started go to the menu and select Disk Utility and then delete all of the partitions, then reformat the drive as one GUID APFS partition.
-
Now exit Disk Utility and start the OS installer letting it do its thing! Your system will reboot a few times and the screen will also go dark so don’t panic!! In a few hours your system should have finished the OS install. Now before doing anything else apply all of the needed updates as needed. Again your system will beboot as Apple has updated the system firmware a few times depending which macOS you are installing.
+
Now exit Disk Utility and start the OS installer letting it do its thing! Your system will reboot a few times and the screen will also go dark so don’t panic!!
+
+
In a few hours your system should have finished the OS install. Now before doing anything else apply all of the needed updates. Again, your system will reboot as Apple has updated the system firmware a few times depending which macOS you are installing.
At this point you need to wipe the drive and re-install your OS from an external OS installer drive.
First backup anything important off your drive (TimeMachine)
Next create a bootable OS installer using another Mac system, I personally would stick with Mojave for now as Catalina is still a bit buggy! In any case here’s how to create both:
* [https://www.macworld.com/article/3284378/how-to-create-a-bootable-macos-mojave-installer-drive.html|How to create a bootable macOS Mojave installer drive]
* [https://www.macworld.com/article/3442597/how-to-create-a-bootable-macos-catalina-installer-drive.html|How to create a bootable macOS Catalina installer drive]
Restart your system then using the Option key to enter into the Startup Manager select the USB-C installer drive. Once started go to the menu and select Disk Utility and then delete all of the partitions, then reformat the drive as one GUID APFS partition.
Now exit Disk Utility and start the OS installer letting it do its thing! Your system will reboot a few times and the screen will also go dark so don’t panic!! In a few hours your system should have finished the OS install. Now before doing anything else apply all of the needed updates as needed. Again your system will beboot as Apple has updated the system firmware a few times depending which macOS you are installing.
Did that work?