Right click the installer > Show Package Contents > Contents > SharedSupport > locate the file InstallESD.dmg.The set up would appear in your Applications folder. Download the Mountain Lion X installer from the app store.Steps to make a back up of the Moutain Lion X installer Requirements to burn Mountain Lion X: To make a back up of the installer on a physical media you need a DVD or flash drive of 5GB or larger. Second but better option is to burn the installer before proceeding for the Mountain Lion X update. First is to re-download the file by pressing down the option key while clicking on the purchase tab or to get the installer back by using the Time Machine backup.Ģ. There are two ways to keep the Mountain Lion set up for installation:ġ. Like the previous Mountain Lion's update, this time too, the installer disappears from the applications folder as soon as the update is finished.

Having a hard copy of the installer will be useful in case you have to do a clean install of the system of want to install Mountain Lion X on a hacked Machintosh. Though after purchasing your copy of Mountain Lion X from the app store you can install the OS n number of times afterwards, but if you would prefer to keep an offline backup of it then here are the steps to make a bootable copy of Mountain Lion X on your USB or DVD. Here are the steps to burn the Mountain Lion X on your USB or DVD. Once you have purchased your copy of Mountain Lion X you might want to make a physical copy of it on CD or in USB drive.

Download mountain lion bootable usb