Mountain Lion Clean Install

Discussion in 'OS X Mountain Lion (10.8)' started by markrox7, Jul 14, 2012.

  1. markrox7 macrumors 6502

    Apr 17, 2011
    Has anyone upgraded to the ML GM with a clean install? If so, how'd you do it?
  2. arashb macrumors 6502

    May 3, 2009
    Depends where you got the image from. If you have it from Apple's seed release you have to right click and go to "Show Package Contents" and look for a file called InstallESD.dmg. If you got it from an unofficial download it may already be the InstallESD.dmg that you're looking at. Once you figure that out you can restore a USB using disk utility and picking the InstallESD.dmg image as the source.

    If you want to burn a disk, I'm guessing it would work by burning the InstallESD.dmg using disk utility.

    This image file is found in Contents>Shared Support. Not entirely positive on that though.

    Then after you boot it up, use Disk Utility in the installer to delete the primary HD where your last OS existed and then exit out of DU and click "Reinstall OS X"
  3. markrox7 thread starter macrumors 6502

    Apr 17, 2011
    Will the process be the same if I want to clean install Mountain Lion when it's publicly released?
  4. arashb macrumors 6502

    May 3, 2009
    Yeah, it should be. If you want to do a clean install with Lion it's the same process. Just right click the install app, go to "Show Package Contents", go to "Shared Support" and copy "InstallESD.dmg" out and use Disk Utility to burn it to a disk or to restore a USB with.

    When I did this with a GM I'd always get an error at the end of creating my USB bootable but everything still worked fine, not sure if that will happen to you.

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