After installing Mac OS X Lion if you facing any trouble like some apps are not working, stuck with a Lion beta version or you just don’t like it and want to downgrade lion to snow leopard then here is the guide to do that. OS X Lion doesn’t allow to downgrade easily so follow the step by step guide to downgrade Mac OS X Lion.
Downgrade Lion to Snow Leopard
Backup through Time Machine on an external disk drive
Insert Snow Leopard DVD or Disk drive. I am using a bootable Snow Leopard USB flash drive and if you have DVD, it doesn’t matter you can use that as well
Restart your Mac, hold the “alt” key from keyboard when you hear the start-up sound
You will see Mac’s boot menu screen as shown below, double click on the OS X Snow Leopard bootable DVD or Disk drive (If you are using DVD you will see a Disc icon instead of USB drive icon)
This will restart your Mac again and boot from selected option either DVD or Disk drive.
Click on Arrow and on the next screen click “Continue” and then “Agree” button
If you see a Yellow icon on the drive, which you want to use to install OS X Snow Leopard then you need to format either Lion partition (if you have multiple partition) or the whole drive
Click on “Utilities” menu and select “Disk Utility”
Formatting Partition or whole disk
If you have multiple partitions then you can select only Lion partition and format it instead of formatting whole drive.
I have only one partition, so i am going to format the whole drive again (i have backup my data in step-1)
- Select the drive from left-side that you want to format
- click on Partition tab
- Select Volume Scheme: 1 Partition
- Type the Volume name: MacSnow
- Choose Format: “Mac OS Extended (Journaled)”
- Click the “Apply” button to format the drive and create a new partition
This will take some time to format it. When done close this window
Now select the drive icon that you just formatted and click the “Install” button
This will start installing the OS X Snow Leopard on your Mac.
When installation finished, click the restart button.
When you restart your Mac, now follow the on screen instructions on few steps to set up your Mac.
So you have successfully downgrade Mac OS X Lion to Snow Leopard.
Restore Time Machine Backup
One of these Mac set up steps you can restore your data from backup that you have taken in step-1 using Time Machine, to do so choose “From a Time Machine backup” option and follow the instructions. Restore process may take hours as it all depends on volume of your data which will get transferred.
If you don’t want to restore data right, don’t worry you can do this later using “Migration Assistant” built-in Mac application