I have had Windows 8 installed with bootcamp on my Mac. The disc was partitioned to allow both Mac and Windows to be used.

When I now go to use MacOS, it begins to start up for a minute then shuts down? The Windows side will start up ok.

When I boot the machine, I have 3 options:

  • Mac
  • Windows
  • Recovery

First, why it this happening? Second, unable to boot to Mac OS X and thus unable to start Boot-Camp Assistant how may I uninstall Windows?

  • 1
    Please try to boot to the recovery disk and verify/repair the Mac volume with Disk Utility. If you get errors, fix them and try to boot again to your Mac system. If no errors occur, try to boot to your Mac system in the verbose single user-mode and add the output to your question.
    – klanomath
    Nov 10, 2014 at 17:20
  • I tried what you suggested! No joy!! Unfortunately the Mac side will not start up so i cannot get into the disk utility. I tried the recovery file as well and nothing! I even left it run on the recovery for over 12 hours and it just wouldn't start up, just had the icon spinning on the screen! Not sure where to turn? I guess its a visit to the Apple store unless you have any more ideas I can try! Thanks very much!
    – Richard
    Nov 11, 2014 at 16:31
  • It's just sorting out some common sources of failure. So it's even impossible to start to the recovery hd? And the verbose su-mode doesn't work either? Do you have a recovery thumb drive? If not try starting to the internet recovery mode (alt-cmd-r), start menubar->utilities/terminal and enter diskutil list and diskutil cs list(each followed by <enter> and add the output to your question.
    – klanomath
    Nov 11, 2014 at 17:03

1 Answer 1


I did something similar and ended up incidentally tweaking the partition table from inside of windows. Because of that it wrecked the EFI and GUID and nearly bricked me completely I thought. Start the computer and hit command-r and you should be able to tell where to go from there. I have to warn you though its probably going to involve wiping one or both partitions. If the EFI table has been altered you're going to have to wipe and clean install to get it back to normal working conditions. Hopefully you can just verify and repair your disk though and that'll do the trick.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .