For personal or business reasons, you may need to install an older version of macOS and Mac OS X on your computer. Indeed, it may be essential in certain situations.
We are thinking in particular, in case you need to test an app or website on an older system, for example. Also, you may just not like the new macOS update.
To change it and go back to an old operating system, different solutions are available to you.
Is your Mac compatible?
Before getting down to business, it’s essential to make sure your Mac is compatible.
Verify that your Mac can run an older macOS version
Before you can reinstall a previous macOS version on your computer, you first need to determine whether your Mac will be able to run it.
If you have a latest generation model, then the hardware drivers may be incompatible with the old software. In this case, they will have great difficulty functioning even with a virtual machine.
Likewise, if you were hoping to get the most recent macOS system on an older Mac, you won’t be able to.
Download the version of macOS, or Mac OS X, of your choice
Is your Mac ready for an older operating system? So now is the time to download the correct installer.
We wrote an article about it, so feel free to take a look to find out how to do it.
Find an old Time Machine backup
If you have a Time Machine backup from before you updated your Mac, you can directly skip to this step that you described below.
However, note that you will not retrieve any added data from it.
Install an older version of macOS on your Mac
Once you’ve downloaded the installer, running the installer isn’t as easy as you might think.
As mentioned above, if your Mac has a recent version of macOS, you won’t be able to find an old one. You will need to completely erase the contents of your Mac beforehand.
Alternatively, you can also save it to an external drive.
The most suitable installation method will depend on a number of factors.
1- Go back to an old macOS version using Time Machine
If you are using Time Machine to back up your Mac, then you can revert to a previous version of macOS. Just follow the steps below:
- Start your Mac by holding down the keys Cmd + R until the Apple logo appears.
- When you see the window Utilities, choose Restore from a Time Machine backup, click on Continue.
- Click again on Continue.
- Choose your Time Machine backup, finish with Continue.
Remember that by recovering an old backup, you will lose the data added since the last update of your macOS.
2- Use macOS Recovery
Thanks to the macOS Recovery it is possible to reinstall the system that originally came with your Mac. To do this :
- Restart your device and simultaneously press Cmd + R.
- Once on Utilities macOS, select Reinstall macOS.
- Click on Continue and follow the on-screen instructions.
- Select your startup disk and click Install.
- Your Mac will restart after installation is complete.
3- Install an older macOS version with a bootable installer
To get started, download the installer for the version of macOS you need from your App Store, then follow the instructions. Next, you will need to use this file to create a program bootable from an external storage device.
After which, proceed with a complete erasure of the contents of your Mac by restoring it to factory settings. To do this, simply turn your computer back on in recovery mode, holding down the keys. Cmd and R sunken.
- Click on Disk Utility, then on Continue.
- Select the primary volume, click Disassemble
- Confirm by pressing Wipe off.
- Finally, click on Reinstall macOS and on Continue
All you have to do is follow the on-screen instructions.
4- Install an old macOS version on an external drive
Running macOS on an external drive is a great way to keep using the current version of your Mac.
Plug in your SSD or HDD, then turn on your Mac while holding down Option / Alt pressed. Following this, choose from which disk you want to continue the installation.
The advantage of this method is that you don’t need to erase your Mac.
The downside is that your computer may be sluggish.
5- Install an old version of Mac OS X on a virtual machine
Mac OS X versions 10.7 can only be used through a virtual machine if the host Mac is running the same system, except for Snow Leopard (10.6).
Therefore, installing OS X 10.8 on a Mac with another version of OS X is a violation of the software license agreement.
However, if you have the software license from Apple, then there are a number of software available that allow you to run multiple versions of macOS on your Mac. These include Parallels, VMware Fusion, Virtual Box.
Also note that Apple’s end user agreement allows Mac OS to run on two virtual machines and on one computer, as long as it is not for business purposes.