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How do I install ML on an external drive?

Discussion in 'OS X Mountain Lion (10.8)' started by Spaceboy88, Feb 17, 2012.

  1. macrumors member

    I just downloaded my version of Mountain Lion from the App Store, but am wondering how I can install it on a separate hard drive as I don't want to overwrite my primary OS. Anyone know how I do this?

    Thank you
  2. macrumors member

    Strange. Seeing as it isn't on the App Store yet :rolleyes:

    Got it from a torrent?
  3. macrumors member

    No, it IS in the App Store if you have an Appleseed Beta Tester download code, which I have.
  4. macrumors regular


    I did the same thing yesterday (instead of an external, i just partition a piece of my HD to run ML in. Installed and expanded, ML is about 10 - 11 GB. I partitioned 40GB so I can have some room to play and test).

    But all you have to do is once you have your partition made (or external loaded onto your mac). Run the installer, it will ask where you want to install it. (just don't point to your main HD).

    After the install, you can reboot your computer, and hold the option key and you will see your various OS instances and you choose the one you want.

    Simple actually.
  5. macrumors member

    Excellent! Thanks.
  6. macrumors 6502a


    How do I get the apple seed download code so I can download ML from the app store so I can do the same install it from my external drive?
  7. macrumors 601


    What do you guys recommend for the ML partition? I was going to try it with in Parallels or like this, I was thinking 20GB. I don't want to download any apps, just play around with the OS.

    Plus, is it easy to delete the partition once ML is actually out?


    You need to be a part of Apple's OS X Developer programme ($99 p/a)

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