This table verifies the Testdisk output by looking at Sector Offset. A negative offset indicates problems.
| GPT3 Start | GPT 3 Size | GPT3 End | Sector Offset | NTFS Start | NTFS Size | NTFS End | Sector Offset (GB) | NTFS Size (GB) |
| 681553696 | 1269536 | 682823231 | 449 | 682823680 | 294281209 | 977104888 | 0.0002141 | 140.3242154 |
This is the correct header.
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 theaction being taken. Gdisk has one-character commands except when entering numbers.
Rebuild GPT4 using start/end offsets
- Sudo gdisk /dev/rdisk0
- P (print the full list of parts)
- D (delete)
- 4 (part 4)
- N (new part)
- 4 (part 4)
- 682823680 ( - Start offset in sectors or the start point for Bootcamp part)
- +294281209 ( - Size offset, as opposed to End offset)
- 0700 (Windows part type)
- P (print list of all parts just to see what changes will be made)
- W (Write the new GPT)
- 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 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.
- Sudo gdisk /dev/rdisk0
- P (Print list of parts)
- R (Recover)
- O (print current Hybrid MBR)
- H (chooses Hybrid)
- Partitions numbers to be hybridized: 2 3 4
- Y (Good for GRUB question)
- N (part 2 boot flag)
- N (part 3 boot flag)
- Y (part 4 boot flag make NTFS bootable partition)
- O (print current Hybrid MBR)
- W (Write the new MBR)
- Y (Yes! write the new MBR)
- 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.
