Mountain Lion on a USB

Ok, so to get Mountain Lion onto a USB use the same method as on Lion

First of all, you will need the following

1. Install OS X Mountain Lion.app (4.37GB download from the Mac App Store)

2. 8GB USB Key

Once you have these you will need to get the Mountain Lion Disk Image, which is obtained by clicking on Finder and pressing SHIFT CMD G at the same time and entering

/Applications/Install OS X Mountain Lion/Contents/SharedSupport/

and then clicking the Go button

Once the folder opens then you need to click on the InstallESD.dmg and press CMD C to copy it, then click on your Desktop and press CMD V to paste it

Once it’s copied to your dekstop rename it 10.8.dmg

Double click on the 10.8.dmg to mount it

Next, insert your USB Key and erase it using Disk Utility as follows

1. click on the device in Disk Utility

2. click on the Erase tab in the middle of the main window

3. choose Mac OS Extended (Journaled) from the format dropdown menu

4. name it Mountain

5. then click the Erase button

6. now click on the Restore tab

7. drag the Mac OS X Install ESD volume onto the Source field

8. drag the Mountain volume onto the Destination field and click on the Restore button

you may be prompted for your admin username and password, so enter this, then the task will start and should take around 15-20 minutes (depending on the speed of your USB2 key)

For a video taking you through the installation process once you have created your USB then click on the link below

Mountain Lion – Reformat & Clean Installation