Previous 1 66 67 68 69 70 Next 1,503 Replies Latest reply: Mar 27, 2016 8:09 AM by osdieman Go to original post Branched to a new discussion.
  • Christopher Murphy Level 3 Level 3

    Hmm, so it's possible Apple's firmware and the Windows bootloaders and kernel have no problem with type code 0x0C. But I'll bet dollars to donuts that Apple's Startup Disk expects to see that partition type code set to 0x07. So if you haven't used setpid in fdisk to change the 0C to 07, try that, write out the new results, reboot OS X and see if Startup Disk now shows it as an option.

  • Number88 Level 3 Level 3

    I too have often wondered about this type code. It's a valid type code for a Windows partition but as you say it's used on a FAT32 partition. Interesting that this case boots ok as is whereas others have not.

    Changing the type to 07 was my next port of call if setting the boot flag didn't work.

    Interesting. Sadly I have no dollars or donuts to gamble with 

    Still learning!

  • Loner T Level 7 Level 7
    Windows Software

    JustAHobbit wrote:


    EFI disk showed up in iStat menu, I had not seen that before. Disk utility verfication suggested me a repair and I did it, after that the EFI disk disappeared and I could not boot to windows.


    Christopher Murphy wrote:


    2.) The user has some other mismatch between the MBR and GPT, runs Disk Utility "repair disk" on the whole disk device, not merely the HFS+ volume, and this causes diskutil to recreate the hybrid MBR.


    Both of these behaviors are wrong. If Windows still boots from type code 0x0C with active bit set then that's fortunate even though it's the wrong code; it's possible Windows 8 could behave differently from Windows 7.


    The 2013 MBPs and MBAs are beginning to support EFI/UEFI but many have had driver issues or things not working as expected, for example Cirrus Audio.


    Not sure how much motivation there is to provide updates to older equipment to bring all on par with EFI/UEFI and migrate many of the current CSM-BIOS/MBR installations to newer ones. Number88 has been involved in some such discussions.


    There are quite a few posts, where people have bought Apple MACs to run Windows, rather than buy the current Dell/Lenovo/Asus/HP offerings.

  • Christopher Murphy Level 3 Level 3

    In my view so long as the official support through Boot Camp Assistant depends on CSM-BIOS booting, that users are better off with other products. There are other limitations than just the hazards of hybrid MBRs and related bugs. I haven't yet seen Mac firmware rebased on UEFI 2.x.

  • ravage484 Level 1 Level 1

    I understand you know how to fix this problem using gdisk commands.  When I followed your guide from earlier, It tells me that I have no partition #5 and that it skipped it.  I cannot get into my windows boot, if you can help I could copy/paste my terminal window.  Thanks!

  • Loner T Level 7 Level 7
    Windows Software

    Can I suggest that you post a link to a new thread here with the output of the following commands? (You can see samples in Dark Fury's post on page 65).


    sudo gpt -r -vv show disk0

    sudo fdisk /dev/rdisk0

    diskutil list


  • PS_STI Level 1 Level 1

    Let me respond: it does not have to be the partition #5. It can be - and in my case it was - partition #4. So I added partition #4 to MBR. I also added the partition #2. Thanks to it I can both boot from Windows AND see the Mac HD from the Windows level.

  • PS_STI Level 1 Level 1



    sudo gdisk /dev/disk0

    r <enter>        go to the recovery & transformation menu
    h <enter>        create a new hybrid MBR
    2 4 <enter>        add partions 2 and 4 to the MBR

    Place EFI GPT (0xEE) partition first in MBR (good for GRUB)? (Y/N): Y

    Creating entry for GPT partition #2 (MBR partition #2)
    Enter an MBR hex code (default AF): <enter>
    Set the bootable flag? (Y/N): N

    Creating entry for GPT partition #4 (MBR partition #3)
    Enter an MBR hex code (default 07): <enter>
    Set the bootable flag? (Y/N): Y

    n <enter>        do not protect more partitions
    o < enter>       print (display) the MBR
    w <enter>

  • tantrumnism Level 1 Level 1

    I too am having issues. i attempted to follow and skim through these posts but have yet been able to complete and boot from windows. my bootcamp shows in system preference and start up disk but doesn't show up when choosing option when booting. Any asistance would be greatly appreciated.




  • tantrumnism Level 1 Level 1


  • Loner T Level 7 Level 7
    Windows Software

    1. I am a bit surprised at the MSR partition. Did you try an EFI boot or a Windows repair?

    2. Your fdisk output shows partition #3 as bootable which is atypical, with Recovery HD missing from the MBR.

    3. What happens when you select Bootcamp partition from Startup Manager on the OS X side? Does Windows boot correctly?

    4. Could you describe the sequence of events which led to the "issue"?

  • tantrumnism Level 1 Level 1

    I tried an EFI boot.

    Initially i upgraded to Mavericks. I added Windows 8.1 on 500gb factory Macintosh HD with no issues.


    I have since replaced this drive with a 128gb SSD and swapped optical drive for caddy including the 500gb HD.


    I cloned Mac OS using Carbon Copy inclusive of recovery partition.


    I used bootcamp to add 8.1 to the SSD and was able to do so with success. Afterward reformated the 500gb HD into 2 partitions a large one for Mac and a smaller one fore Windows files. Since then i've been unable to boot into Windows.


    Within my System Preference > Starup Disk provides the option to boot from Windows Bootcamp but when restarting i get "no bootable disk"


    I am able to see Bootcamp in finder, startup disk option and in disk utility. it just doesn't boot.


    I have since then been in and out of this thread trying several options including creating a 5th partition and creating the Hybrid disk. I am still unsuccessful in my efforts. Here is what things are looking like now. Help!.png

  • Loner T Level 7 Level 7
    Windows Software

    Your GPT partition 4, MBR partition 3 is the Bootcamp partition the way it is right now. There is a dd command that will let you look at the contents to see if you have the OS missing or not. You may need to do a Windows Recovery using a CD/DVD/USB to get windows to boot.

  • tantrumnism Level 1 Level 1

    Windows Recovery using a usb? are you referring to install disk or a recovery disk?

  • tantrumnism Level 1 Level 1

    Still having issues. Any assistance would be much appreciated.


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