2 Replies Latest reply: Jan 20, 2013 8:45 PM by Christopher Murphy
zoltangy Level 1 Level 1

I have installed bootcamp by the bootcamp assistant and worked properly.


Then I have partitioned the OS X 10.8.2 and installed another Mountain Lion System and I have got two MAC boot options and Bootcamp disappeared from the Option menu.


However, Bootcamp still remained in the Startup Disk in the System Preferences.


When I tried to boot Bootcamp using the Startup Disk it did not boot and received a message that there is no bootable device.


I have not lost any data and can read Bootcamp partition from both OS X systems.


Please advise how can I boot Windows / Bootcamp again?


Thank you.


MacBook Pro (Retina, Mid 2012), OS X Mountain Lion (10.8.2), Bootcamp
  • BobTheFisherman Level 6 Level 6

    Start again by removing the extra partition you created on your Bootcamped drive. This time read and follow the Bootcamp Installation instructions. You can't partition a Bootcamped drive.


    Make sure you back up your data first.

  • Christopher Murphy Level 3 Level 3

    Recommendation 1: Use a VM for this. It's essentially a giant C.F. to do this with native booting, and is potentially fragile.


    But if you're going to ignore that and do this anyway, realizing that it can break anytime in particular with OS upgrades, and that it's very difficult to impossible to resize the three volumes once you've installed the systems:


    1. create three partitions, setting each to be the size for OS X copy 1, copy 2, and Windows respectively. The Windows partition needs to be set to MS-DOS format (actually FAT32) which later in the Windows installer you'll reformat as NTFS. Do not use Boot Camp Assistant to resize/partition the disk, it simply won't work for this use case.

    2. install OS X copy 1

    3. install OS X copy 3

    4. Use gdisk (available at sourceforge) which is a command line only application, to create a new hybrid MBR adding only the last partition (Windows) to the hybrid MBR and setting it to be bootable. As a concequence you will not be able to see/share either OS X volume from within Windows. The Windows NTFS volume will be visible from within OS X.

    5. Install Windows to the only partition its installer should see (confirm size), you'll need to format it NTFS first, and I suggest using the fast format option if available.