Please help! Missing OSX partition

Discussion in 'macOS' started by RedW6lf, Mar 21, 2014.

  1. RedW6lf macrumors newbie

    Mar 21, 2014
    Hello, I am new to this forum and OSX in general. I've recently purchased a used 2011 Macbook Pro (sweet deal!) and soon afterwards began to install Windows 8 via bootcamp. Needless to say it was an extremely frustrating process, but I eventually was successful in installing it. Windows was up and running just fine, minus an audio driver issue which I couldn't care less about at this moment. Anyways, I realized shortly afterwards that I was unable to boot into OSX. Apparently during the windows installation process all of my partitions seemed to merge together. Now, all I have is a "BOOTCAMP" partition. For now I am stuck in Windows and I am in desperate need of help to get OSX back up and running. Can anyone please help me?? I've spent hours trying to figure this out to no avail. I sincerely appreciate any advice and information whatsoever! By the way I do NOT have the original osx installation disk for the computer.
  2. revbarabbas macrumors regular

    Apr 27, 2009
    Silly question, but did you hold down the "Option" key when you tried to boot back into OS X?
  3. maflynn, Mar 22, 2014
    Last edited: Mar 22, 2014

    maflynn Moderator


    Staff Member

    May 3, 2009
    One of two things happened.
    Either you're in windows and the default partition is now BOOTCAMP. As mentioned holding down the option key during boot up will display all boot able partitions. Installing the apple bootcamp drivers/utilities has an option of selecting the startup volume in windows as well

    The second possible cause is you installed windows on your OSX partition. That is during the formatting phase of installing windows, you selected the OSX partition and its not longer there. If that is the case, then its gone for good and you need to rebuild the machine, i.e., hold down the Command-R key to enter into the recovery partition.
  4. RedW6lf thread starter macrumors newbie

    Mar 21, 2014
    This is what i get when i boot into recovery and then choose the option to "reinstall Mac OS X". As you can see i only have one partition and it is "locked". I imagine i would have to do something in disk utility to unlock the disk, but i don't know which step to take next. If it comes down to me having to replace windows with OSX then i don't mind losing windows. Is there anything i can do? Thanks for the help guys :)

    Attached Files:

  5. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    Restart and get back to recovery and from the main recovery screen launch Disk Utility. Now select the drive band name at the very top (like 1TB Seagate or whatever). Now go to the File menu and select Unlock (although I think you can skip this). Now go to the erase tab and select Mac OS Extended (Journaled) and name the volume Macintosh HD then apply the change. This should erase the entire disk to one, large OS X partition.

    Once the erase is done just quit Disk Util then click Reinstall OS X.


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