Q: Bootcamp fails after Yosemite upgrade (Plz help me Loner!)

Please run the Quick Search, and press Enter to Continue when you see unrecoverable partitions listed. This should result in a list of recoverable and viable partitions.

The most likely candidate is at the following NTFS Start (the MS Data prior to the highlighted entry. The repeated size column is also a clue).

Please scroll up to that entry and use 'P' to list files. You should see something similar to the following...

If you notice, your 500Gb is split into 280Gb OSX CS Container, and your Windows is 110Gb, leaving roughly about 100GB missing. The lost NTFS header indicates a size of 200+ GB (GB vs GiB calculations can be confusing a bit). Please use the following steps.

Install GPT Fdisk (aka gdisk).  Leave your Testdisk display and start a new Terminal Window. You need to use the following steps. If you see any error messages during the following steps, please stop and post back here with the error message. The following steps have values from your Testdisk output (and you can verify) in Steps 7 and 8. Please notice the'+' sign in step 8 (this is called offset notation). The text in parentheses is for informational purpose to describe the action being taken. Gdisk has one-character commands except when entering numbers.

Rebuild GPT4 using start/end offsets

1. Sudo gdisk /dev/rdisk0
2. P  (print the full list of parts)
3. D  (delete)
4. 4  (part 4)
5. N  (new part)
6. 4  (part 4)
7. 548554752 ( - Start offset in sectors or the start point for Bootcamp part)
8. +428550137 ( - Size offset, as opposed to End offset)
9. 0700 (Windows part type)
10. P  (print list of all parts just to see what changes will be made)
11. W (Write the new GPT)
12. Y  (Yes! really write the new GPT)

This will delete and re-write the GPT partition info for /dev/disk0s4.

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. 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: 2 3 4
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 #2 (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 #3 (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 #4 (MBR partition #4)

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

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

Test 1 - Does Bootcamp Volume show up in Finder?

Test 2 - Can you see files in Bootcamp Volume?

Test 3 - Can you select Bootcamp in System Preferences -> Startup Disk?

Test 4 - If Test 3 is successful, select Bootcamp and Click Restart.

How long was the bar allowed. chkdsk can take a bit of time. If you have the original installer, can you boot from it and try Startup Repair?

If you can get to command prompt, try a manual chkdsk /f .

Please backup OSX and Windows to separate external physical disks and keep as a baseline for future recovery. You can use Time Machine for OSX and Windows Backup/Restore (or File History) to make backups.

Hi All,

Seems I have a similar problem but don't feel comfortable repeating the steps above, as my config is slightly different. Please see the screenshots from Testdisk and also output from other disk-related utilities

The highlighted >D MS Data partition is the one containing the "System Volume Information"

Other info - Partition Inspector from rEFIt:

Here is the output of the diskutil list

Przemeks-MacBook-Pro:~ Przemek$ diskutil list

/dev/disk0

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                        *500.3 GB   disk0

   1:       Microsoft Basic Data EFI                     209.7 MB   disk0s1

   2:                  Apple_HFS Macintosh HD            371.2 GB   disk0s2

   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3

   4:       Microsoft Basic Data Bootcamp                128.2 GB   disk0s4

Here is the output of the sudo gpt -r -vv show disk0

gpt show: disk0: mediasize=500277790720; sectorsize=512; blocks=977105060

gpt show: disk0: MBR at sector 0

gpt show: disk0: Pri GPT at sector 1

gpt show: disk0: Sec GPT at sector 977105059

      start       size  index  contents

          0          1         MBR

          1          1         Pri GPT header

          2         32         Pri GPT table

         34          6       

         40     409600      1  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

     409640  724998784      2  GPT part - 48465300-0000-11AA-AA11-00306543ECAC

  725408424       1368       

  725409792    1269536      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

  726679328        224       

  726679552  250425344      4  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

  977104896        131       

  977105027         32         Sec GPT table

  977105059          1         Sec GPT header

Here is the output of the sudo fdisk /dev/disk0

Disk: /dev/disk0    geometry: 60821/255/63 [977105060 sectors]

Signature: 0xAA55

         Starting       Ending

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

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

1: AF   25 127  15 - 1023 254  63 [    409640 -  724998784] HFS+      

*2: 07 1023 254  63 - 1023 254  63 [ 726679552 -  250425344] HPFS/QNX/AUX

3: EE    0   0   2 -   25 127  14 [         1 -     409639] <Unknown ID>

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

Your GPT has alignment gaps, which are normal. The partition should look like this given your Testdisk output.

Use the values in steps 7 and 8 on the first set of Gdisk steps and test.

The order in MBR is non-standard. Was a third-party partitioning tool used to re-arrange/create the MBR (like iPartition or PartitionMagic)?

Hi Loner T (and others)...I upgraded to El Capitan last night and as soon as it was complete, I could no longer boot into my Bootcamp partition that contains Windows 10.  From reading your previous posts, it seems like there might be a solution after changing the GPT values, but i'm not skilled in identifying the correct values, but can go thru your steps once I know the correct values.  An item that also might be a factor...I few months ago I used a third-party partitioning utility to increase the size of the Bootcamp partition (I think it was PartitionMagic)...as soon as I did that I could no longer boot Windows from the Mac Startup Disk option or could see the Bootcamp partition in Disk Utility...the only way I could boot Windows was to restart and hold Alt/Option key.  But after the EC upgrade, Windows is not an option when I hold Alt/Option.  Here is my output from TeskDisk...let me know if you need any additional screenshots:

Is it odd that the Bootcamp partition 4 is listed twice with the same Start/End parameters?

thanks in advance!