After updating to Maverick, Windows 7 bootcamp partition can't mount

My situation was identical to the that of the following post:

Re: Can't access Bootcamp after partition

So I followed Chris' posted instructions and ended up with the required "*4: 07" (see below, computer name removed). I've rebooted but the partition is still appearing as "disk0s4" in its greyed out state in disk utility. Still not getting the option to boot into Windows 7 when I use the alt/option key.

Blair

Current view of the bootcamp partition in Disk Utility:

FYI, if it helps, this happened after installing Maverick to update my OS 10.6.8. I believe 750 GB is the correct size of the Windows 7 Bootcamp partition. I mention that because a lot of people with a similar issue seem to report the partition size being incorrect after the OS update. Hoping that's a good sign.

Posted on Aug 1, 2014 9:17 AM

72 replies

Aug 19, 2014 8:35 AM in response to blairoverthere

This is why I suggested fixing the GPT with gdisk first and foremost. Unless 3rd party NTFS read/write support is enabled, it's safe for OS X to automount the Bootcamp volume because it does this read-only and attempts no repairs. If it mounts read-only then the filesystem is probably OK which is good, and then it's OK to create the new hybrid MBR based on the GPT, and then go run Windows Startup Repair.

Otherwise, you're using two different command line programs = much higher chance of user error, including creating a hybrid MBR that's not matched up with the GPT. And OS X only uses the GPT. So Test Disk results are best translated to gdisk and hence the GPT. And then use gdisk to create the hybrid MBR. And then use Windows Startup Repair.

Aug 19, 2014 8:40 AM in response to Loner T

Not if the GPT contains the wrong entries. OS X only honors the GPT entries. I don't recall how these particular test disk entries were arrived at, and if they were plugged into gdisk/GPT first. My suggestion is that only if you get testdisk to successfully navigate the chosen NTFS filesystem, and show some user files, should you trust that particular suggested start/end value pair. Then use gdisk to remove the wrong Bootcamp partition entry in the GPT, add a new entry with the correct values from gdisk, write out the modified GPT, and reboot. If OS X now automounts the Bootcamp volume, you can make a hybrid MBR with gdisk. If not, then you have to go back a step and make certain you've not made a mistake entering in the testdisk values: if testdisk can navigate and see files, then OS X should mount the volume read-only and you should see files. If that isn't happening, don't proceed further, find out why that's not working.

Aug 19, 2014 4:14 PM in response to Christopher Murphy

Well I didn't get these last couple til after the disk repair had started. It completed after about 5 hours and instructed me to reboot. When I did, it tried to continue the repair but said it couldn't continue. So I booted back into MacOS and now the partition is auto-mounting and it's being labelled "BOOTCAMP". And in Finder and I see many files and folders. But not all of them (most notably my documents folder isn't there). Is there more I can at this point? Hybrid MBR, GPT corrections, any of the stuff like that, or is likely this as good as it gets?

Aug 19, 2014 4:59 PM in response to blairoverthere

What did you use for disk repair?

I would return to the Windows install media, and run chkdsk /f to make sure the volume is clean. And then use bootrec.exe manually to try to get the system bootable again, assuming chkdsk /f comes up clean. If not then you can see if testdisk sees your documents and can extract them from the Bootcamp volume. And if that also fails then I'd suggest a Linux Live CD/DVD on a USB stick, and an SDHD card or another USB stick or a drive partition that you can reformat: you'll format it as NTFS from within the Linux live environment, and see if you can copy your files from Bootcamp to alternate media - all before giving up and blowing away the Bootcamp volume (which can simply be done in the Windows installer BTW you don't have to mess around with Bootcamp Assistant unless you want a different Windows volume size first).

Loner T

Level 9

59,536 points

Aug 19, 2014 6:00 PM in response to blairoverthere

blairoverthere wrote:

When I did, it tried to continue the repair but said it couldn't continue.

1. Were there any errors?

2. After the reboot, can you switch to Windows via System Preferences -> Startup Disk -> Windows. If yes, it should continue repairs.

blairoverthere wrote:

So I booted back into MacOS and now the partition is auto-mounting and it's being labelled "BOOTCAMP".

Did you power cycle to boot OS X?

Loner T

Level 9

59,536 points

Aug 19, 2014 6:03 PM in response to Christopher Murphy

I think the repair is incomplete, and if Windows can boot, it will continue.

Aug 20, 2014 11:00 PM in response to Christopher Murphy

After the initial 5-hour repair, it rebooted after ejecting the Windows 7 repair CD. This time, it showed the Windows 7 OS as one that could use repair. I attempted to continue the repair. But quickly, it gave the following message:

Startup Repair cannot repair the computer automatically

Clicking on "Show Details" I got:

Problem Event Name: StartupRepairOffline

0.0.0.0

6.1.7600.16385

unknown

-1

AutoFailover

OsVersionMismatch

OS Version: 6.1.7600.2.0.0.256.1

So I went to the command prompt and ran chkdsk /f and all seemed well. I repeated the bootrec.exe procedures. But it basically does this whole thing over again if I try to reboot. And yes, I power cycled. Thoughts? The files that do show up seem valid. I double clicked on an image file in Finder from this BOOTCAMP partition and it came up fine. Would say easily the majority of files are still missing though. Maybe something about the version mismatch error? I just went to try setting the Windows partition as the startup disk in System Prefs but it wasn't offered as an option..

Loner T

Level 9

59,536 points

Aug 21, 2014 6:56 AM in response to blairoverthere

blairoverthere wrote:

Clicking on "Show Details" I got:

Problem Event Name: StartupRepairOffline

0.0.0.0

6.1.7600.16385

unknown

-1

AutoFailover

OsVersionMismatch

OS Version: 6.1.7600.2.0.0.256.1

Were any Service Packs applied to your installation after the initial install? You seem to have minor version mismatches. .16385 vs. .2.0.

blairoverthere wrote:

I just went to try setting the Windows partition as the startup disk in System Prefs but it wasn't offered as an option..

As Christopher pointed out, the GPT is out-of-synch with the MBR, hence OSX does not know what to provide. If you correct the GPT, it should work.

Aug 29, 2014 2:34 PM in response to Loner T

So currently, I'm able to access a portion of the files (see pic). Of course, I'd love to access all of them if that's possible--especially the _Documents folder which currently shows as empty. How do I correct the GPT and create the hybrid MBR with gdisk?

PS., with regard to the versions of Windows 7, I'm not sure what the exact release of Windows 7 was so I can't account for that slight difference in version IDs. I made the recovery CD on a different Windows 7 machine that I have. I can't seem to get my iMac to take the Windows7 DVD or any DVD for that matter. That's why I made the recovery CD.

Aug 29, 2014 4:19 PM in response to Loner T

FYI, maybe not useful, but here's what testdisk outputs currently if I select "Intel/PC" partition:

Aug 29, 2014 4:20 PM in response to Loner T

And if I select EFI/GPT partition map:

Loner T

Level 9

59,536 points

Aug 29, 2014 5:10 PM in response to blairoverthere

This looks positive. Are you still running into startup repair issues?

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After updating to Maverick, Windows 7 bootcamp partition can't mount