Repairing Boot Camp after creating new partition

Your above solution solved my problem partially. Here is my partition layout:

Windows 7 was installed using Bootcamp. Then I used the Mac Disk Utility to shrink the Macintosh HD partition & carved out Windows 8 partition out of it. After that I used gdisk as described in your reply (that fixed Scocth_Brawtch problem) to make the Windows 7 partition visible at boot time as it wasn't avaible when I had created the Windows 8 partition. Then I installed rEFit and used Windows 8 DVD to load the Windows8 to the partition using the newly created partition. After I rebooted I could see 3 choices from rEFit screen:

1. Mac
2. Windows on Partition 2
3. Windows from HD

When I booted using Windows HD I was taken to Windows8 and I could no longer boot to Windows7. Then I went back to Mac and as per your directions made Windows7 as the boot disk. Now I am unable to boot to Windows8.

Anytime I have to boot to the other Windows partition I have to follow the "gdisk" procedure to make it bootable from the rEFit screen.

Also I am unable to see separate partition of Mac and Windows when I boot from either Windows 7 or 8. In windows it shows me GPT protected partition on Disk Management and as combined partition.

The Bootcamp one is Windows7. I have to the your process everytime I have to switch between Windows 7 and Windows 8, which ever I have to boot to.

Can you help with that? If you want anymore information just message me.

Thanks in advance

Kunal Bajpai

Yeah this is just too complicated for the various tools you're trying to use, none of which understand hybrid MBRs very well, except gdisk which can only create them rather than understand all possible intents. I'd just say this isn't supportable, at least it's not something I would do on Apple hardware. I would use a VM, or I'd get a computer with real firmware for booting Windows and Apple doesn't make such a thing.

Hello, Christopher, I have a question for you, because as it seems like, you know the stuff 🙂

Here's what I did:

At first I had Macintosh HD and Bootcamp partition.

Then I booted to Mac, went to Disk Utility, and created a new partition on my Macintosh HD. And then I formated it for MS-DOS (FAT), so that I could see it in Windows and then later formated it in windows for NTFS.

And then the first problem was that I couldn't boot to Windows 7 - but I solved this with your instructions below.

I did everything you already said in the first page of this topic about the gdisk ...

To recap:

*************

sudo gdisk /dev/disk0

If you get any error messages at this point, report the error messages, don't proceed further.

You're now in gdisk interactive mode. Menus/commands are single characters followed by return/enter. So type ? and <enter> and you'll get the main menu listing commands. Type p <enter> and it will print (display) the current GPT. Since you have 5 GPT entries, you can't use a 1 for 1 GPT to MBR scheme like Apple does. The following suggestion is safe, but all hybrid MBRs are non-standard inventions, and therefore I can't tell you how Boot Camp Assistant or Disk Utility will react to this hybrid MBR should you decide to make changes later. What I can tell you is Windows, Linux, and Mac OS X themselves have no problem with this MBR scheme.

r <enter> go to the recovery & transformation menu

h <enter> create a new hybrid MBR

5 <enter> add partion 5 to the MBR

<enter> accept the default MBR hex code of 07

y <enter> set the bootable flag

n <enter> do not protect more partitions

o < enter> print (display) the MBR

You should have two entries. One type EE, one 07, with the 07 entry marked with * under Boot. If you don't, report back. If you do, write out the update partition information, and hope a power failure doesn't occur for the next few seconds...

w <enter> write partition table to disk

*************

BUT results for my commands were as follows:

sudo gpt -r -vv show disk0

gpt show: disk0: mediasize=1000204886016; sectorsize=512; blocks=1953525168

gpt show: disk0: Suspicious MBR at sector 0

gpt show: disk0: Pri GPT at sector 1

gpt show: disk0: Sec GPT at sector 1953525167

start size index contents

0 1 MBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 387349760 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

387759400 262872

388022272 587702272 3 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

975724544 6416384

982140928 971382784 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

1953523712 1423

1953525135 32 Sec GPT table

1953525167 1 Sec GPT header

AND the diskutil list command:

4: Microsoft Basic Data BOOTCAMP 497.3 GB disk0s4

Therefore I used 4 instead of 5 in your instructions (in the original topic the 5 was for BOOTCAMP).

Then ... after I completed everything, I booted with holding the option key and could normally start into Windows.

BUT HERE is the next PROBLEM: Now I can't see any of my Macintosh HD and my newly created Macintosh MS-DOS (FAT) partition.

I wanted to format the newly created partition and merged it with my current Bootcamp partition in Windows.

BUT what seems to be the problem now? If I boot to MacOS, I can see just everything fine; I see all disks and everything. But I lost my 2 partitions in Windows.

How can I resolve this issue now, without doing everything from scratch?

I hope you have a solution 🙂

Thanks!

when i enter the command sudo gdisk /dev/disk0 i get error 2

it asks type device file name.

Christopher!

I just installed Mavericks and it broke my BootCamp.

I only have 2 partitions, real simple. one mac, one bootcamp.

The Bootcamp drive is gone, and it shows up in diskutility as "Disk0s4"

anyway to fix this using your magic terminal commands?

Frank

So what you need to do is go back through those steps to create a new hybrid MBR, and instead of adding only partition #4 to the MBR, add 2 3 4 and only mark the one with Windows as bootable - presumably that's 4 since that's what you did before it worked. For what it's worth, there's a 3 GB gap of unused free space between partitions 3 and 4. So at some point you'll want to back everything up and start from scratch.

No idea. Provide the result from:

sudo fdisk /dev/rdisk0

sudo gpt -r -v show /dev/rdisk0

Thanks Chris,

here's the screenshot:

and btw, i had Windows 7 installed and it was formatted NTFS, I beleive.

Try the 2nd command again you didn't include the gpt part.

Hi, also having this issue.

The problem is the 4th partition in the MBR has the wrong type code and isn't marked bootable. So you can either fix this using fdisk or gdisk. The gdisk method is probably better documented in this thread. The fdisk method is faster.

sudo fdisk -e /dev/disk0

setpid 4

07

flag 4

write

Just done it. Now with holding Alt button I can see Windows, but when I choose it, prints only "Missing operating system"

There is a large 28GB gap between partitions 3 and 4. My guess is this is the result of an aborted attempt at using Disk Utility to modify the partitions of the disk, something Apple really needs to disallow once a disk has been "bootcamped". Their documentation indirectly says this, basically if you need to make changes you have to blow away Windows with Bootcamp Assistant and start from scratch anytime you want to make any change. But Disk Utility will let you get into big, big trouble.

Anyway, can you confirm/deny that you can see the bootcamp volume in OS X? Can you navigate the folders within that bootcamp volume, and find your stuff on it? If you can, then Windows Startup Repair should be able to fix this problem. If you don't have a volume named BOOTCAMP automounted while you're in OS X, then it's a lot trickier.