how to clean install 10.7?

Discussion in 'Mac OS X Lion (10.7)' started by littleasian, Feb 26, 2011.

  1. littleasian macrumors member

    Jun 20, 2009
    i recently got a copy of the 10.7 dmg. how do i go about clean installing it on my macbook pro (2009)? i know for iso files you can simply burn it on a dvd with disc utility, does that work for dmg's as well?

    i'd prefer not to do an upgrade installation from SL to Lion.

  2. Hellhammer Moderator


    Staff Member

    Dec 10, 2008
    You should not replace your main OS with Lion as it's still in very early beta stage and may not be stable and support all the apps you need. Create a partition with Disk Utility and install it there. That way you will have both, 10.6 and 10.7.
  3. littleasian thread starter macrumors member

    Jun 20, 2009
    yea i'm aware of the risks but since i usually just use safari/office 11 i think i'll be ok.
  4. newfoundglory macrumors 6502

    Nov 5, 2007
    I installed Lion on my Mid 2010 mac mini server and 2008 MBP.

    The mac mini doesn't have an optical drive, so i used a spare external USB hard drive, created a few partitions (must be GUID) on it and then restored Lion dmg contents to one of those partitions (all done using Disk Utility). You can then boot the installer by holding alt/option key on startup and selecting what you just restored. If you created a few partitions on the USB HDD, you can even install Lion back to one of those partitions on the USB disk and boot of it rather than the internal hard drive of your Mac if you prefer (i didn't).

    It was so easy off USB that I repeated the process on my MBP.

    Lion is very stable. I'm very surprised.
  5. littleasian thread starter macrumors member

    Jun 20, 2009
    hrmm that sounds pretty easy but i don't have any spare external's lying around. do you have any idea how i would go about doing this with a dvd-r?
  6. simsaladimbamba

    Nov 28, 2010
    I used Disk Utility to partition my internal HDD into two partitions, one for the existing SL installation, and one for the coming Lion installation.
    I then used CarbonCopyCloner to clone the DMG's contents to a USB thumbdrive with 4GB capacity and installed Mac OS X via that thumbdrive without problems.
    To do a clean install, you might be able to use these steps: Clean Install of OS X 10.6 Snow Leopard
  7. newfoundglory macrumors 6502

    Nov 5, 2007
    Not tried it personally with Lion, but it should work if you burn it to DVD with Disk Utility. Just hold C on startup.
  8. antmarobel macrumors 6502


    May 8, 2009
    If you wanna do a clean install:
    after the language choice, click on Apple menu and chose "quit install" ( at least I think is "quit install" since in Portuguese this is the meaning...;)) In the following window chose Disk Utility and run it as usual if you wanna send your SL back to Himalyan! :D as I did). After the erase process, close Disk Utility and click in install Mac OS X!!!!

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