Repairing boot camp after OS install 10.10.2

Question

In response to this on another thread.  After a reinstall of 10.10.2 my bootcamp partition won&#x27;t start. (Windows 7). I can see the bootcamp partition in finder, but when i try to boot to it i get "missing boot disk" error.Please post the output of1. diskutil list2. sudo fdisk /dev/&lt;DiskWhereYouHaveInstalledBootcamp&gt;3. sudo gpt -v -r show /dev/&lt;DiskWhereYouHaveInstalledBootcamp&gt;/dev/disk0   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *750.2 GB   disk0   1:                        EFI EFI                     209.7 MB   disk0s1   2:                  Apple_HFS Macintosh HD            678.5 GB   disk0s2   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3   4:       Microsoft Basic Data BOOTCAMP                70.8 GB    disk0s4Mikes-MacBook-Pro:~ Mike$ diskutil cs listNo CoreStorage logical volume groups foundMikes-MacBook-Pro:~ Mike$ sudo fdisk /dev/disk0Password:Disk: /dev/disk0 geometry: 91201/255/63 [1465149168 sectors]Signature: 0xAA55         Starting       Ending#: id  cyl  hd sec -  cyl  hd sec [     start -       size]------------------------------------------------------------------------1: EE 1023 254  63 - 1023 254  63 [         1 - 1465149167] &lt;Unknown ID&gt;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    Mikes-MacBook-Pro:~ Mike$ sudo gpt -vv -r show /dev/disk0Password:gpt show: /dev/disk0: mediasize&#x3D;750156374016; sectorsize&#x3D;512; blocks&#x3D;1465149168gpt show: /dev/disk0: PMBR at sector 0gpt show: /dev/disk0: Pri GPT at sector 1gpt show: /dev/disk0: Sec GPT at sector 1465149167       start        size  index  contents           0           1         PMBR           1           1         Pri GPT header           2          32         Pri GPT table          34           6                  40      409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B      409640  1325164720      2  GPT part - 48465300-0000-11AA-AA11-00306543ECAC  1325574360     1269544      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC  1326843904   138303488      4  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7  1465147392        1743          1465149135          32         Sec GPT table  1465149167           1         Sec GPT header

Loner T · Answer

Can you post the output of sudo dd if&#x3D;/dev/rdisk0s4 count&#x3D;1 2&gt;/dev/null | hexdump -CYour MBR is now a protective MBR, which should not be the case. Was your Windows installation a standard Bootcamp Assistant install or an EFI install?What year/model is your Mac?

mrgazz · Answer

Loner T · Answer

Download GPT Fdisk (http://sourceforge.net/projects/gptfdisk/files/) and install it. Run the following steps.Rebuild MBR to match the new GPT information thus resetting the Hybrid MBR.Use defaults for other questions (for example Enter an MBR hex code (default AF): AF).Sudo gdisk /dev/disk0P  (Print list of parts)R   (Recover)H (chooses Hybrid)Partitions numbers to be hybridized: 2 3 4Y (Good for GRUB question)N (part 2 boot flag)N (part 3 boot flag)Y  (part 4 boot flag make NTFS bootable partition)W  (Write the new MBR)Y    (Yes! write the new MBR)RebootTest 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 -&gt; Startup Disk?Test 4 - If Test 3 is successful, select Bootcamp and Click Restart

mrgazz · Answer

That fixed it.  Thank you, you are amazing!  The apple support guy told me i would just need to remove and reinstall my bootcamp  partition and that my data was gone.  I knew he was wrong and am so glad I came here for advice. Again, many thanks!

Loner T · Answer

Good to see it work with a simple fix. 😎