I recently installed Windows 8 on a Mac with boot camp. The partition was working fine. However, I recently reinstalled OSX and now I am unable to select the Windows partition upon startup. How can I fix this issue?


2 Answers 2


I had the same issue, this fixed it for me:

sudo fdisk -e /dev/disk0
flag 4

Apparently it wasn't flagged as active: http://www.reddit.com/r/mac/comments/2eo7dq/win7_bootcamp_hd_not_showing_up_as_startup_disk/


It will start booting on OSX and then display a dual boot. I was on the same situation and the problem was solved. The software is in demo mode.

  • I tried BootChamp, it's free but on my Yosemite install, it hangs.

I think you just have to find a way to boot on your Windows 8 partition and go to your Windows 8 Bootcamp settings to reset the boot disk to Windows 8. This will update the Master Boot Record to set your Windows 8 as a bootable disk.

You could think about using your Windows 8 installation or recovery disk to repair your installation. You could also try to see on OSX if you Windows disk is available in

System Preferences > Startup Disk and define it as the startup disk.

When you succeed booting in Windows 8, you will likely be able to reset the boot disk to your OSX partition and retrieve your dual boot.

You must log in to answer this question.

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