I have read a few posts and answer but I am not quite sure...

I was on Catalina and for multiple compatibility reasons, I need to go back on Mojave. I did a time machine back up on Catalina, erased the startup disk and Mojave (which my Mac was shipped with) is now installing. What is going to happen when I restore from my Catalina time machine backup?

I don't want the OS restored. I want everything I had on Catalina switched to Mojave.


If you already have the system software installed, time machine will install your personal files and the files you select. It will not install the system software.

See this answer for more detail.

  • Thank you for the answer. I confirm, everything went all fine!
    – Jacques
    Jun 20 '20 at 3:08

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .