dgnhlp

Q: Lost boot ability to OSX and Windows 10

So I had a working bootcamp install of Windows 10 and was able to switch back and forth between WIN10 and OSX. I decided I wanted to also install Linux so I went into OSX and cut a partition off of the OSX install. This caused me to lose ability to boot into Windows 10.

 

Using very limited research and some of the commands found in this thread: Repairing Boot Camp after creating new partition I managed to make things worse and ended up unable to boot to either OS. I ended up installing windows 7 on the partition I created for Linux and that is now the only thing I am able to boot into.

 

Is there anyone who can help me repair my MBR through windows 7 to restore access to my windows 10 and OSX partitions?

 

I appreciate any help in advance!

MacBook Pro

Posted on Aug 23, 2015 12:45 PM

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Q: Lost boot ability to OSX and Windows 10

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  • by dgnhlp,

    dgnhlp dgnhlp Aug 24, 2015 9:58 AM in response to Loner T
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    Aug 24, 2015 9:58 AM in response to Loner T

    I'm now booted into OSX and ready for further instruction

  • by Loner T,

    Loner T Loner T Aug 24, 2015 10:12 AM in response to dgnhlp
    Level 7 (24,202 points)
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    Aug 24, 2015 10:12 AM in response to dgnhlp

    For the record please post the output of the following OSX Terminal command.

     

    sudo gpt -vv -r show /dev/disk0

  • by dgnhlp,

    dgnhlp dgnhlp Aug 24, 2015 10:19 AM in response to Loner T
    Level 1 (0 points)
    Aug 24, 2015 10:19 AM in response to Loner T

    gpt show: /dev/disk0: mediasize=500107862016; sectorsize=512; blocks=976773168

    gpt show: /dev/disk0: Suspicious MBR at sector 0

    gpt show: /dev/disk0: Pri GPT at sector 1

    gpt show: /dev/disk0: Sec GPT at sector 976773167

          start       size  index  contents

              0          1         MBR

              1          1         Pri GPT header

              2         32         Pri GPT table

             34          6        

             40     409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

         409640  195305824      2  GPT part - 48465300-0000-11AA-AA11-00306543ECAC

      195715464    1269536      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

      196985000       1880        

      196986880  193849344      4  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

      390836224  585936896      5  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

      976773120         15        

      976773135         32         Sec GPT table

      976773167          1         Sec GPT header

     

     

     

     

    sorry if the formatting is bad

  • by Loner T,

    Loner T Loner T Aug 24, 2015 10:51 AM in response to dgnhlp
    Level 7 (24,202 points)
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    Aug 24, 2015 10:51 AM in response to dgnhlp

    No worries about formatting. . Looks clean. Please test switching between the two OSes and visibility to the Shared partition after the following steps. You will not be able to see the OSX partition from the Windows side, because it will be combined with Recovery HD.

     

    This is not a standard Hybrid MBR. Standard MBR contains GPT 2,3,4 but we are using GPT3,4,5.

     

    Rebuild MBR to match the new GPT information thus resetting the Hybrid MBR. Use defaults for other questions (like partition codes). The only values that need modifications are the Boot flags and step 10. Accept all other defaults that Gdisk offers. Please see the sample Q&A as an example. These steps can be repeated if you make a mistake before you get to Step 12, otherwise start from Step 1 for these steps. Step 6 has numbers which are typed with a space between the numbers.

    1. Sudo gdisk /dev/rdisk0
    2. P  (Print list of parts)
    3. R  (Recover)
    4. O (print current Hybrid MBR)
    5. H (chooses Hybrid)
    6. Partitions numbers to be hybridized: 3 4 5
    7. Y  (Good for GRUB question)
    8. N  (part 2 boot flag)
    9. N  (part 3 boot flag)
    10. Y  (part 4 boot flag make NTFS bootable partition)
    11. O  (print current Hybrid MBR)
    12. W (Write the new MBR)
    13. Y (Yes! write the new MBR)
    14. Reboot

     

    Here is sample Q&A for this section. Please notice the Press Enter/Return.

     

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

     

    Creating entry for GPT partition #3 (MBR partition #2)

    Enter an MBR hex code (default AF): Press Enter/Return

    Set the bootable flag? (Y/N): N

     

    Creating entry for GPT partition #4 (MBR partition #3)

    Enter an MBR hex code (default AB): Press Enter/Return

    Set the bootable flag? (Y/N): N

     

    Creating entry for GPT partition #5 (MBR partition #4)

    Enter an MBR hex code (default 07): Press Enter/Return

    Set the bootable flag? (Y/N): Y

  • by dgnhlp,

    dgnhlp dgnhlp Aug 25, 2015 8:38 AM in response to Loner T
    Level 1 (0 points)
    Aug 25, 2015 8:38 AM in response to Loner T

    I now have 3 options at boot. Mac OSX, Windows, and EFI Boot. Both EFI Boot and OSX boot to osx. and Windows boots to the emergency windows 7 installation i made, not the windows 10 installation im looking for.

     

    Here are some outputs I thought you might ask for:

    Capture.PNG

    Capture2.PNG

     

    edit: by the way i apologize for the delayed responses. I'm active duty military and receiving training about 10-12 hours a day during the weekdays so I don't get a whole lot of time to play with this. I really appreciate the help though.

  • by Loner T,

    Loner T Loner T Aug 25, 2015 10:13 AM in response to dgnhlp
    Level 7 (24,202 points)
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    Aug 25, 2015 10:13 AM in response to dgnhlp

    Thank you for your service to whichever country's Armed Forces you are serving. Post back when you have time. . One suggestion is to switch to OSX if possible, since it has richer tools to go further.

  • by dgnhlp,

    dgnhlp dgnhlp Aug 29, 2015 11:19 AM in response to Loner T
    Level 1 (0 points)
    Aug 29, 2015 11:19 AM in response to Loner T

    Sorry for taking so long to respond. I am booted into OSX and ready for further instructions for recovering the win 10 partition. I have all day today and tomorrow open for working on this.

     

    Thanks again!

  • by Loner T,

    Loner T Loner T Aug 29, 2015 2:41 PM in response to dgnhlp
    Level 7 (24,202 points)
    Safari
    Aug 29, 2015 2:41 PM in response to dgnhlp

    We fixed your OSX booting issue using Widows 10 Gdisk commands. You should be able to switch between OSX and Windows using Boot Camp: Set the default operating system or using the Alt/Option key during power up/down cycle.

     

    Your W10 should also boot normally now. Please test. If you see any issues with W10 or missing W10 drivers, please post back.

  • by dgnhlp,

    dgnhlp dgnhlp Aug 29, 2015 2:50 PM in response to Loner T
    Level 1 (0 points)
    Aug 29, 2015 2:50 PM in response to Loner T

    No I have 3 options at boot. Mac OSX, Windows, and EFI Boot. Both EFI Boot and OSX boot to osx. and Windows boots to the emergency windows 7 installation i made on the partition that i made (which originally messed everything up), not the windows 10 installation i'm looking for.


    I still have no access to windows 10.

  • by Loner T,

    Loner T Loner T Aug 29, 2015 2:56 PM in response to dgnhlp
    Level 7 (24,202 points)
    Safari
    Aug 29, 2015 2:56 PM in response to dgnhlp

    From the MBR perspective, the Windows that is currently booting is GPT#5 which is 279GiB. Is the 92GiB partition the Windows 10 partition?

  • by dgnhlp,

    dgnhlp dgnhlp Aug 29, 2015 3:04 PM in response to Loner T
    Level 1 (0 points)
    Aug 29, 2015 3:04 PM in response to Loner T

    279 is the windows 10. But windows 7 (92gb) is what boots when I choose windows and also when I chose to restart into windows from within osx

  • by Loner T,

    Loner T Loner T Aug 29, 2015 3:10 PM in response to dgnhlp
    Level 7 (24,202 points)
    Safari
    Aug 29, 2015 3:10 PM in response to dgnhlp

    Can you check the available options in System Preferences -> Startup Disk?

  • by dgnhlp,

    dgnhlp dgnhlp Aug 29, 2015 3:42 PM in response to Loner T
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    Aug 29, 2015 3:42 PM in response to Loner T

    BOOTCAMP windows, and Mac osx.

  • by Loner T,

    Loner T Loner T Aug 29, 2015 3:57 PM in response to dgnhlp
    Level 7 (24,202 points)
    Safari
    Aug 29, 2015 3:57 PM in response to dgnhlp

    If you select the Bootcamp Windows, which version of Windows do you get?

  • by dgnhlp,

    dgnhlp dgnhlp Aug 29, 2015 3:59 PM in response to Loner T
    Level 1 (0 points)
    Aug 29, 2015 3:59 PM in response to Loner T

    it doesn't tell me which version that one is but if i click to restart into that one it still goes to windows 7.

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