Apple OS X Mountain Lion 10.8 clean installation tutorial


Download & Installation


You can download OS X Mountain Lion from the Mac App Store and upgrade from OS X Lion 10.7 or do a clean install from an external hard drive or a DVD. I will offer a quick tutorial on installing OS X 10.8 from a 8GB USB drive since the MacBook Air does not have an optical drive.

The upgrade process from OS X 10.7 Lion to OS X 10.8 Mountain Lion is pretty self explanatory so i will not offer a tutorial on that. If you prefer a clean installation you can follow the steps below.


What you will need


A copy of OS X 10.8 Mountain Lion which you can purchase from the Mac Apps Store;

A USD drive larger than 4.8 GB;

A compatible Mac (check the list below to make sure your Mac is compatible with OS X 10.8 Mountain Lion before the purchase);

  • iMac (Mid 2007 or newer)
  • MacBook (Late 2008 Aluminium or Early 2009 or newer)
  • MacBook Pro (Mid/Late 2007 or newer)
  • MacBook Air (Late 2008 or newer)
  • Mac Mini (Early 2009 or newer)
  • Mac Pro (Early 2008 or newer)
  • Xserve (Early 2009)


Download

 

The above link should take you to the Mac App Store Mountain Lion download page.



You will have for the download to finish depending on your internet connection.

 

 

Installation


After the Mac App Store has finished the download you can find the OS X Mountain Lion installer app in your Applications folder.


You can now right click (ctrl + click) the OS X Mountain Lion installer app and select Show Package Contents. Open the Contents folder then the SharedSupport folder. This is where you will find the InstallESD.dmg file.
Copy this file to your Desktop. Make sure you use Copy and Paste, simply dragging the file to your desktop might only create an alias.

Double clicking the file you have just copied to your desktop will mount the disk image and open a finder window showing its contents.



You can close this window and open the Disk Utility. Just hit command + space and start typing "disk utility". Now you can also connect your USB drive to your Mac.


Select the USB drive and click the Erase tab. Choose Mac OS X Extended (Journaled) as Format and click the Erase button.


Now select the USB drive you have just formatted and click in the Restore tab.
Note that under Source the drive itself is selected.


Click on Mac OS X Install ESD and drag it to the Source field.
Now click on the USB drive you have formatted before and drag it to the Destination field.
Your Disk Utility window should now look something like this:


Click Restore and confirm will loose all it's data and enter the admin password when requested.

The Disk Utility will now create a bootable OS X Mountain Lion 10.8 USB drive.
This process can take between 20 and 50 minutes depending on your computers performance.

When finished, backup your data (this type of installation will erase all the data on your Macs hard drive), reboot your mac and hold down the option ket.
You can now select the bootable USB drive (shown as an orange drive) and begin the OS X installation.


Do you have any questions or suggestions? Please leave a comment.