


Reinstalling an earlier backup will undo all the changes you made since creating this backup, so make sure all of your documents and data are stored somewhere safe before proceeding.
#How to download mac os x sierra to non compatible imac update#
If you create regular Time Machine backups (and you should!) then you may be able to reverse a macOS update by restoring a Time Machine backup that you created before installing that update. Choose your startup disk, and then select ‘Install.’.

Once you see the macOS Utilities screen, select ‘Reinstall macOS’ and then click ‘Continue.’.Restart your Mac, while holding down the ‘Shift+Option+Command+R’ keys.If you’re on High Sierra 10.12.4 or later, and you want to revert to the version of macOS that shipped with your Mac, then you’re in luck! This is one of the easiest ways to downgrade your Mac:
