I have a MacBookPro 2011, OSx 10.9.2, it is dual booted (using bootcamp). I followed this youtube video that shows how to resize mac


but after resizing the OSx partition, I was not able to boot into the bootcamp (Windows 7). I have searched for this issue, and I think the problem is because there is no synchronization between MBR and GPT.

this is the report from Partition Inspection in Mac:

enter image description here

Please note that I have access to the Mac OS, but I can't access the Windows 7 (bootcamp).

when I reboot, the windows 7 partition appears, but when I click on it show "Missing Operating System"

Please help me...


It seems you now have a situation where the GPT partition table and the MBR partition table disagree about the start/end boundaries of the Windows partition. You can try the following method, but you'd better make a backup for Mac OS before doing this.

  1. Take the shrunk space back to MAC OS.
  2. Boot from OS X install media and open up a command prompt.
  3. Type fdisk /dev/disk0 to see the MBR partition table. Write down the partition number (it's usually 4), the start sector, and the size of the Windows partition. The start sector and size will be big numbers so make sure you write them down correctly. This is critical.
  4. Type diskutil unmountDisk /dev/disk0 This will unmount the disk so GPT can write to it.
  5. Type gpt remove -i 4 /dev/disk0 NOTE: that the '4' here references the partition number of your Windows partition you got from fdisk earlier. This will delete the GPT partition entry for your Windows partition.
  6. Type fdisk -d /dev/disk0 >/Volumes/fdisk.txt This will make a backup of the MBR partition table.
  7. Type fdisk -e /dev/disk0 to put the fdisk command in interactive edit mode. And enter the following commands: e 4 0 q y
  8. Type diskutil unmountDisk /dev/disk0 again because the gpt command caused OS X to remount the disk and we need to modify it again.
  9. Type gpt add -b -s -i 4 -t windows /dev/disk0 where 'start sector', 'size', and '4' are the values you wrote down from the fdisk command earlier.
  10. Type gpt show /dev/disk0 to view the GPT table. Make sure the partition number, start sector, and size match the fdisk output from step 3 EXACTLY.
  11. Type diskutil unmountDisk /dev/disk0 again because the gpt command caused OS X to remount the disk and we need to modify it again.
  12. Type fdisk -r -y /dev/disk0
  13. Type fdisk /dev/disk0 to view the MBR table. Make sure the output matches the fdisk output from step 3 EXACTLY.
    After that, both Mac and Windows should be bootable.

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