MacTavish_10
Level 1 (9 points)

Q: Repairing Boot Camp after creating new partition

Hi


I'm running OS X 10.9 and Windows 7 x64 Pro.

 

I set up Boot Camp to dual-boot Windows on my MacBook Pro Retina. Everything was fine. And just yesterday Apple released the Yosemite Beta for the public and I wanted to download this and give it a try. After some research, I found that creating a separate partition was the way to go, and so I made another partition.

I wasn't aware that this would affect my Windows partition as I thought it was completely different.


So now, when I boot up, there is no option to boot with Windows. But when I boot the Mac and select Startup Disk, it shows Boot Camp is still there and all my files etc are still there.


I have a 256SSD, 160GB was for the Mac, and I have 90GB set for Windows.


I made the new partition to 40GB (and the Mac was now 120GB).

 

Then once I completed that part, I restarted my Mac and the Windows boot option was no longer there.

 

I didn't even install the Yosemite yet. I went to Disk Utility and deleted the 40GB partition that I made.

 

Now I don't know what to do. I have a lot of important things which are still on my Windows. Is there a way to restore normal Boot Camp functionality?

MacBook Pro (Retina, 13-inch, Late 2013), OS X Mavericks (10.9.4)

Posted on Jul 25, 2014 8:20 AM

by Loner T,Solvedanswer
Loner T Loner T
Level 7 (23,898 points)
Safari
A:

sudo fdisk -e /dev/disk0

p

setpid 4

07

flag 4

p

write

y

 

Now Reboot and hold the ALT key and check if Windows shows up and is bootable.

 

If you get 'missing operating system', then Windows Startup Repair and see if Windows will comeback alive.

 

If you notice the difference between the Disk Utility screen (two partitions) vs the fdisk output (or the GPT) there are 'hidden' partitions and the MBR partitioning style used for Windows allows a maximum of 4 partitions. If you need further explanation, read the original thread.

 

Yosemite should not be installed on any machine that is critical to you. If only partitioning was done, but Yosemite was NOT installed, you are in better shape. Yosemite ignores and is unaware of bootcamp and creates an additional Recovery HD and moves things around.

Posted on Jul 25, 2014 9:04 AM

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Q: Repairing Boot Camp after creating new partition

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  • by joaomalveiro,

    joaomalveiro joaomalveiro Sep 23, 2014 5:25 AM in response to Loner T
    Level 1 (0 points)
    Sep 23, 2014 5:25 AM in response to Loner T

    jcmm@jcmm ⭕  ~ sudo fdisk /dev/disk0

    Disk: /dev/disk0 geometry: 31130/255/63 [500118192 sectors]

    Signature: 0xAA55

             Starting       Ending

    #: id  cyl  hd sec -  cyl  hd sec [     start -       size]

    ------------------------------------------------------------------------

    1: EE 1023 254  63 - 1023 254  63 [         1 -  500118191] <Unknown ID>

    2: 00    0   0   0 -    0   0   0 [         0 -          0] unused     

    3: 00    0   0   0 -    0   0   0 [         0 -          0] unused     

    4: 00    0   0   0 -    0   0   0 [         0 -          0] unused

  • by Loner T,

    Loner T Loner T Sep 23, 2014 5:35 AM in response to joaomalveiro
    Level 7 (23,898 points)
    Safari
    Sep 23, 2014 5:35 AM in response to joaomalveiro

    Your MBR looks clean. Under System Preferences -> Startup Disk click on OS X and then click on Restart. Test again with a power cycle.

  • by joaomalveiro,

    joaomalveiro joaomalveiro Sep 23, 2014 5:44 AM in response to Loner T
    Level 1 (0 points)
    Sep 23, 2014 5:44 AM in response to Loner T

    weird.. now i restarted to check it and it's fixed, maybe one random command i entered yesterday before posting my problem here solved the issue. I thought it didn't because it returned an error.

     

    I think this was the one i entered: sudo fdisk -e /dev/disk0.

  • by Loner T,

    Loner T Loner T Sep 23, 2014 6:00 AM in response to joaomalveiro
    Level 7 (23,898 points)
    Safari
    Sep 23, 2014 6:00 AM in response to joaomalveiro

    This fdisk -e is the interactive mode of fdisk. If you modified the MBR by hand and flagged an entry to be bootable, boot manager will keep picking it up till you change it via System Preferences.

  • by ashmathcom,

    ashmathcom ashmathcom Oct 24, 2014 11:28 AM in response to Loner T
    Level 1 (0 points)
    Oct 24, 2014 11:28 AM in response to Loner T

    I would be grateful if you could help me.

    I have the same issue (i have yosemite 10.10. i partitioned and resized my macintosh hd. and i lost bootcamp start up)

    I can see it in my drives. But i lost as startup disk and when i hold down option key there is no windows 7

     

    here are my screen shots:

     

    1.jpg

    2.jpg

     

    3.jpg

    11.jpg

     

    22.jpg

  • by Loner T,

    Loner T Loner T Oct 24, 2014 11:33 AM in response to ashmathcom
    Level 7 (23,898 points)
    Safari
    Oct 24, 2014 11:33 AM in response to ashmathcom

    Can you start a new thread and post images using an external Image sharing website (I use IMGUR, but you use any you want)?

     

    Please remove personal information, if you do not want it visible on a public forum.

  • by ashmathcom,

    ashmathcom ashmathcom Oct 24, 2014 11:46 AM in response to Loner T
    Level 1 (0 points)
    Oct 24, 2014 11:46 AM in response to Loner T

    Repairing Boot Camp after creating new partition

  • by elyoe011,

    elyoe011 elyoe011 Nov 24, 2014 5:10 AM in response to Loner T
    Level 1 (0 points)
    Nov 24, 2014 5:10 AM in response to Loner T

    Loner T,

     

    I did this fix:

     

    sudo fdisk -e /dev/disk0

    p

    setpid 4

    07

    flag 4

    p

    write

    y

     

    When I started Windows all I had was a black screen with a blinking underscore "_"

     

    I went back to my MAC and try it again... but instead of "setpid 4" and "flag 4" I did "setpid 1" and "flag 1"

     

    Now when I boot into Windows/BootCamp  is saying "Missing Operating System" and OS X is not bootable.

     

    Also Macintosh HD is gone from Disk Utility when I go into recovery mode and check Disk Utility...

     

    I there any REMEDY for this? I have a lot of data that I need to recover...

     

    ANY help is really appreciated!!!!!!!!

  • by Loner T,

    Loner T Loner T Nov 24, 2014 5:33 AM in response to elyoe011
    Level 7 (23,898 points)
    Safari
    Nov 24, 2014 5:33 AM in response to elyoe011

    Do you want to start a new thread in the Bootcamp Discussions and post the information of the following four commands

     

    diskutil list

    diskutil cs list

    sudo gpt -vv -r show /dev/disk0

    sudo fdisk /dev/disk0

     

    Partition 1 is EFI/ESP is never marked bootable. OSX Bootability is derived from EFI/ESP and the GPT entries. Teh only entry that requires MBR-based bootability is Windows/Bootcamp partition, nothing else.

  • by elyoe011,

    elyoe011 elyoe011 Nov 24, 2014 5:46 AM in response to Loner T
    Level 1 (0 points)
    Nov 24, 2014 5:46 AM in response to Loner T

    YES!! Do I have to start a new thread? How do I revert what I have done?

     

    THANK YOU for the quick response!!!!!

  • by elyoe011,

    elyoe011 elyoe011 Nov 24, 2014 6:24 AM in response to Loner T
    Level 1 (0 points)
    Nov 24, 2014 6:24 AM in response to Loner T

    Loner T,

     

    I created the following thread:

     

    Repairing Boot Camp after creating new partition

     

    I need to know how to revert what I did? Thanks again!!

  • by elyoe011,

    elyoe011 elyoe011 Nov 24, 2014 7:17 AM in response to Loner T
    Level 1 (0 points)
    Nov 24, 2014 7:17 AM in response to Loner T

    Loner T,

     

    How can I access the Console from boot? I have tried Command (⌘)-S and Command (⌘)-V but nothing happens, still showing "Missing Operating System"

     

    Sorry for the many posts, I'm just trying to get this fix because is critical for me! I really appreciate your or any other help I can get.

     

    Again, I started the below threat:

    Repairing Boot Camp after creating new partition

  • by u935,

    u935 u935 Dec 31, 2014 6:16 AM in response to Loner T
    Level 1 (0 points)
    Dec 31, 2014 6:16 AM in response to Loner T

    Thank you Loner T

  • by Sagittarius 16,

    Sagittarius 16 Sagittarius 16 May 10, 2015 10:27 AM in response to MattTheMedic
    Level 1 (0 points)
    May 10, 2015 10:27 AM in response to MattTheMedic

    I also problem restore macbook I use window 7dvd  and my Mac can't restart wen I insert window 7 DVD I follow instruction but can install I need mbr

  • by Godiex,

    Godiex Godiex Aug 2, 2015 10:42 PM in response to Loner T
    Level 1 (0 points)
    Aug 2, 2015 10:42 PM in response to Loner T

    After years of searching these forums anonymously looking for solutions, I  just created a user to join the support community for the first time, to say THANK YOU LONER T. I followed your instructions through several different pages regarding connected questions, in every answer you were super clear and always with great spirit. : ) thanks man, much appreciated.

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