Lastly, you would be far better off fixing what's wrong with your Mac than to downgrade to an earlier operating system. Beware that if any of them have been updated to work with Sierra, they may no longer work with El Capitan or earlier OS X versions.
Then, restore your files from the backup.
#Revert to previous imac operating system how to
Read the * note to determine how to force Internet Recovery.Shut down your Mac, and restart it using macOS Internet Recovery.A confirmation message will appear, informing you about the reinstallation details. To downgrade your Mac’s operating system from macOS 10.15 Catalina to another compatible version, you will need to back up your Mac, save important files, erase the internal hard drive, and then install macOS. Afterward, you simply need to follow this basic drill to reinstall macOS on your system. When you get the macOS utility window on the screen, you can just click on the ' Reinstall macOS ' option to proceed.
#Revert to previous imac operating system mac os x
To learn how to use Time Machine read Use Time Machine to back up or restore your Mac.Īfter you have that backup and are satisfied with your ability to recover its files - or you decide that you do not need or want any of the information on that Mac, and understand that it will be irretrievably and forever lost, continue with the steps below. Step 4: Reinstall Mac OS X without Losing Data. Please refer to macOS Sierra: Revert to a previous macOS version.Īssuming you have no Time Machine or equivalent backup of your essential files and other documents, create one now because you will need to completely erase that Mac in order to downgrade its operating system from Sierra to any earlier version.