Are you wanting to downgrade Mac OS X 10.9 Mavericks to Mac OS X 10.8 Mountain Lion? Or maybe even further back, to Lion? The good news is that you can roll back your Mac to the operating system that was first installed on it using a Recovery Disk.

Then our guide to rolling back the Mac OS X operating system to an earlier version has the information you need.

First of all it’s worth noting that you cannot simply take Mac OS X back to an earlier edition and keep all of your files. When Mac OS X updates to the latest version it updates the file structure in apps like iPhoto, iTunes, Calendar, Mail and so on. Apple doesn’t create any system that enables you to roll back to an earlier version and keep all these files, so you can’t take these files with you.

But it is possible to perform a clean installation of the older operating system, and you can also backup your current data and then start to transfer it across.

It’s by no means easy to roll back to an earlier operating system, and we wouldn’t advise it unless you have a real need to be on the older operating system (say if you have a vital program that requires the older operating system, or you're testing out on an older operating system). But for general use Mavericks is better than Mountain Lion in almost all respects (including speed) so we’d suggest you stick with the newer operating system if possible.

Step 1: Get a copy of Mac OS X Mountain Lion

Check for Install Mac OS X file

The first thing you need to do is get a copy of the Mountain Lion installation file. You may already have this if you’ve done an install before. Open the Applications folder and check for the Install Mac OS X Mountain Lion folder.

If you haven’t go this file, then you’ll need to go hunting for it. If you purchased it from Apple then you can open the App Store, and click on Purchases. Look for the Mountain Lion purchase and click on Download next to it. This will download the Installer file to your Applications folder.

If you haven’t purchased it you need to buy a copy from Apple. You can’t buy one from the App Store. Instead click on this link to buy a copy of Mountain Lion from Apple (for £14) You receive a code that you can enter into the App sTore to download the app.

See: How to buy old Mac OS X software: pick up older operating systems for Apple Macs

Step 2: Download recovery Disk Assistant.

Get recovery assistant

You can get a copy of Recovery Disk Assistant from Apple. Click here to get Recovery Disk Assistant (click Download). You’ll need this. Double click the Recovery Disk Assistant.dmg file in Downloads to continue.

Step 3: Create a recovery install disk

Erase Drive

Now create a recovery drive. This is an external drive (usually a USB Flash drive) that you use to create a recovery disk. Follow these steps

  1. Open Disk Utility (click on Go, Utilities and double-click Disk Utility)
  2. Select the recovery drive in the sidebar and click on Erase
  3. Ensure that the Format is Mac OS X Extended and click on Erase and Erase.
  4. Click Partition and change Current to 1 Partain
  5. Click options and select GUID Partition Table.
  6. Make sure the format for the partition is Mac OS Extended (Journaled).
  7. Click Apply.

Now open the Recovery Disk Assistant program. and click on Agree. Click and choose the external hard drive in the middle of the window and click Continue. Enter your password and click OK.

See: Apple Support: Erase and reinstall OS X

Recover Assistant

Step 4: Clone your hard drive

It’s important to make a clone of the whole hard drive and keep it around for a while. This can be useful in case of emergencies (you can boot from the hard drive) and you can re-clone it back to the main drive if there’s a problem. Also you can keep this around and pick files from it to copy over to the rolled back installation. The best way to do this is using a program like Carbon Copy Cloner or SuperDuper along with an external hard drive. Choose your main hard drive in the source, and your external hard drive in the Destination. Now click on Clone.


Step 5: Restart the Mac in Recovery Mode

First of all make sure you are connected to the Internet (open Safari and browse around). You need an internet connection to install Mac OS X. Restart the Mac by clicking on Apple > Restart and hold down the Command and R keys until the Recovery Mode Utilities window appears.


Step 6: Erase the drive

Select Disk Utility and click on Continue. Now choose your Startup Disk in the sidebar on the left, and click on the Erase tab. If you want to securely erase the drive choose Security Zero Data One-Pass. Click Erase to delete the hard drive. Note that this permanently erases all data on the hard drive so don’t do this unless you’ve cloned the drive or are happy to never have to get something from that drive again. When Disk Utility has finished exit the program by choosing Disk Utility and Quit Disk Utility.


Step 7: Reset and restore

Reset the Mac and hold down the Alt key and choose the Recovery USB drive. Install the OS X version that is provided with Internet Recovery, it depends upon what originally came on the machine (typically it will be either Lion or Mountain Lion). Note that if you have a Mac with an optical drive you can also use the installation disc to install direct to that operating system.

To find out more about Mavericks, read our Mac OS X Mavericks Review. Also, we answer the question: Mac OS X Mavericks vs Mac OS X Mountain Lion: should I upgrade? 

We have also published a series of tips on how to master Safari in Mavericks. You can also find our Maps tips here. Finally, read how to use two screens at the same time in Mavericks.