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Created a new partition and now bootcamp isn't recognized

Hi, I am hoping some one can help me. I saw the thread here (Repairing Boot Camp after creating new partition), but I had a hard time following and my configuration might be different.


I have an iMac with boot camp, and created a new partiiton. Now my windows boot camp won't start. I see it in system preferences > startup disk as an option to start up in, but when I so I get "no bootable disk" message.


If i restart and hold down option, I only see my mac drive to boot into and not the windows partition


Here is my system info:

Boot camp is disk0s5

User uploaded file


User uploaded file

User uploaded file


I would so appreciate any guidance in getting my boot camp bootable again.

iMac (27-inch Mid 2011), OS X El Capitan (10.11.2)

Posted on Jan 8, 2016 12:33 PM

Reply
7 replies

Jan 8, 2016 4:20 PM in response to jesse4216

A. We need to disable SIP.


1. Boot into Local Recovery (Command+R).

2. Start Utilities -> Terminal.

3. Type csrutil disable in Terminal and press Enter/Return.

4. Type csrutil status.

5. Boot normally, and type csrutil status to confirm that all individual entries are still disabled.


B. Rebuild non-standard MBR.


The following steps are non-standard because there is a third user-visible partition. Typically, there are two such partitions in a normal configuration on a single-disk Mac with OS X and Bootcamp. This is fragile and lack of proper backups can lead to potential data loss. Download GPT Fdisk from http://sourceforge.net/projects/gptfdisk/ and install it on the OS X side. The following steps are executed when booted in OS X. If the 20.5G is converted to Free Space, these numbers (3 4 5) will change back to (2 3 4). You can use GParted to extend current BC partition, when you are ready.


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 thesample 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. Please see the sample Q&A before you execute these steps.

  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 3 boot flag)
  9. N (part 4 boot flag)
  10. Y (part 5 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. Accept defaults offered by Gdisk.


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 or AB): 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 or 0B or 0C): 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


Reference:

[Help] Can't boot to windows (8.1) after resizing partition

Jan 8, 2016 1:55 PM in response to Loner T

Thank you! It worked! You saved me.

I still have the partition I made which started this mess. Can I still use it? So on my 1 drive I have in the iMac, I have my el captain partition, a boot camp partition (NTSF), and a third partition which is fat. I wanted to have a shared drive that both operating systems can write to.


You think I am ok with this? Thanks again!

Jan 8, 2016 3:23 PM in response to jesse4216

The current layout is limited by the number of entries allowed in a MBR which is four (4). Since you have five GPT entries, we have to compromise.


The compromise is


GPT1+2 = MBR1 (EFI+OSX)

GPT3 = MBR2 (Recovery HD)

GPT4 = MBR3 (SHARED)

GPT5 = MBR4 (Windows).


This layout makes OS X unreadable, because the EFI is FAT and OS X is HFS+ and there is no Windows driver to read such an animal. The other three entries are there for obvious reasons.

Created a new partition and now bootcamp isn't recognized

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