Hit Apply to format the drive (this will completely erase it). Select the Partition tab, select “1 Partition” from the dropdown menu and choose “Mac OS Extended (Journaled)” for the format type.
If you’re burning to DVD: insert your disc, select the DMG file in the sidebar, and click on “Burn”.Open up Disk Utility from your Applications > Utilities folder and drag the DMG file into the sidebar on the left.Head to Contents > SharedSupport and look for the file called “InstallESD.dmg” Find the installer in your Applications folder and right-click on it then select “Show Package Contents”.Download Lion from the Mac App Store - but don’t install it yet (because of the disappearing installer issue noted above).The steps for burning Mountain Lion to disk are essentially the same as the ones used for Lion: DIY Option: Use OS X’s Built-in Disk Utility Lion Disk Maker finds your copy of Lion downloaded to your Applications folder, asks you what media type you want to use to create the install disk, then handles the rest.
