I need to use an application that needs Mountain Lion and is not yet compatible with Sierra which I upgraded to. How do I go back to Mountain Lion?

OS X Mountain Lion

OS X Mountain Lion

Product No Longer Available

3 Answers from the Community

  • Answer

    I have a similar problem and I plan to partition my hard drive and re-install Mountain Lion in its own partition. Then I can choose to boot up in either Mountain Lion or Sierra. While in Mountain Lion, I then plan to plug in my back-up disk and *hope* the old applications will run from their previous back ups. Don't know for sure if this is going to work, but it's worth a try. It would cost me a fortune to switch from my older versions of Adobe Photoshop and Word to the newer versions...wish I had thought of that before upgrading. I never even wanted to upgrade, I liked my system the way it was, but was forced into the upgrade because Chrome and Safari no longer supported my OS. :(

  • Restore from a backup would be a solution.
    If no backup is available re-install the OS using HT204904


    Ensure you have your important data before you do anything...

  • If your mac was shipped with Lion(2011), you can do Internet Recovery (Immediately after hearing the Mac boot chime, hold down Command+Option+R). It will install the original OS that your computer was shipped with. I hope yours came with Lion