Get the latest version of the Mountain Lion installerīefore you make a bootable install drive, you should make sure you have the latest version of the Mountain Lion installer. If you don’t, you’ll have to re-download the installer from the Mac App Store before you can create a bootable install drive.)

So if you plan to use that installer on other Macs, or-in this case-to create a bootable drive, be sure to copy the installer to another drive, or at least move it out of the Applications folder, before you install. (Note: As explained in our main Mountain Lion-installation article, if you leave the Mountain Lion installer in its default location in the Applications folder when you install OS X 10.8, the installer will be deleted automatically after the installation finishes. That said, if, for whatever reason, you absolutely need to create a bootable install DVD, follow steps 1 through 5 under “ Using Disk Utility,” below, but from Step 6 on, follow the instructions under “To create a bootable DVD” in our article on making a bootable Lion-install drive. In addition, you can easily update a USB stick or external hard drive each time an update to Mac OS X is released, as explained below with a DVD, you have to toss the disc in the trash and start over, which is both a hassle and bad for the environment. More and more Macs ship without a built-in optical drive booting and installing from a DVD is very slow and 8GB flash drives can be found for $10 or less-there’s little reason to opt for a DVD anymore. Though it’s possible to make one, I don’t recommend it these days. You may have noticed that I didn’t mention making a bootable install DVD.

Osx mountain lion install disk