Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Redyoshi510 Author

Level 1

1 points

I can't boot to Windows after resizing my Mac partition.

So, I recently decided to resize my bootcamp Win7 partition. This is something I have done successfully before, by:

1) Booting into Macintosh

2) Using Disk Utility to decrease the size of the Mac partition (20GB the first time)

3) Booting into Windows

4) Using Mini-Tool Partition Wizard (third-party) to allocate the free space to the Bootcamp partition.

There were a couple issues caused by this the first time around, mainly the fact that Macintosh didn’t recognize the fact that the free space had been taken, and had trouble reading from the Windows partition. However, I could live with that. I have since rebooted to both Mac and Windows several times without problem.

Recently, I decided I needed a bit more space, and so started to follow the above steps, shrinking the Mac partition an additional 15GB. Only when I went to reboot to reallocate the space, the Windows partition didn’t show up as a bootable option. Confused, I booted back to Mac, and the Bootcamp partition was still there, but renamed “disk0s4”, and unmounted. Reparing the disk failed (“Invalid BS_jmpBoot in boot block: 15921e”). The disk wouldn’t mount (not even sure if it was supposed to be mounted earlier, but that’s what it looks like). It also appears grayed-out in the list of drives to the left. It looks like I can create a dmg from the windows drive, although I haven’t done that yet (I will soon).

Any solutions for this? Although I will erase the drive if absolutely necessary, it would be preferred if that wasn’t the first option to try. I had no problems like this the first time I resized the disk.

(My mac partition is running Mavericks, if that is of any relevance)

MacBook, OS X Mavericks (10.9), Mid-2010 MC516

Posted on Aug 6, 2014 6:04 AM

50 replies

Loner T

Level 9

59,471 points

Aug 16, 2014 9:22 AM in response to Redyoshi510

The 'R.NTFS' is really promising. Can you restart the Mac and hold the Alt key and check if you can select Windows and try and boot?

Redyoshi510 Author

Level 1

1 points

Aug 16, 2014 9:56 PM in response to Loner T

Hmm... Nope, the Windows partition has disappeared from the list of bootable disks once again.

Redyoshi510 Author

Level 1

1 points

Aug 30, 2014 10:19 PM in response to Loner T

Any suggested course of action?

Loner T

Level 9

59,471 points

Aug 31, 2014 5:27 AM in response to Redyoshi510

After you corrected the GPT and MBR, is there a Bootcamp volume visible on the OS X side?

You may also want to post

sudo gpt -vv -r show /dev/disk0

sudo fdisk /dev/disk0

just to ensure there was nothing left missing.

Redyoshi510 Author

Level 1

1 points

Aug 31, 2014 9:00 AM in response to Loner T

The Bootcamp volume is visible on the mac side.

gpt command:

fdisk command:

Loner T

Level 9

59,471 points

Aug 31, 2014 9:43 AM in response to Redyoshi510

I get an error trying to look at the images on my Mac as well as iPhone. Can you post test versions of the output?

Redyoshi510 Author

Level 1

1 points

Aug 31, 2014 11:26 AM in response to Loner T

Test or text? I'm not sure what you would mean by test so I'm going to assume text.

gpt:

gpt show: /dev/disk0: mediasize=250059350016; sectorsize=512; blocks=488397168

gpt show: /dev/disk0: Suspicious MBR at sector 0

gpt show: /dev/disk0: Pri GPT at sector 1

gpt show: /dev/disk0: Sec GPT at sector 488397167

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 166015624 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

166425264 1269544 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

167694808 29298216

196993024 291403769 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

488396793 342

488397135 32 Sec GPT table

488397167 1 Sec GPT header

fdisk:

Disk: /dev/disk0 geometry: 30401/255/63 [488397168 sectors]

Signature: 0xAA55

Starting Ending

#: id cyl hd sec - cyl hd sec [ start - size]

------------------------------------------------------------------------

1: EE 0 0 2 - 25 127 14 [ 1 - 409639] <Unknown ID>

2: AF 1023 254 63 - 1023 254 63 [ 409640 - 166015624] HFS+

3: AB 1023 254 63 - 1023 254 63 [ 166425264 - 1269544] Darwin Boot

4: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

Yikes, looks like the format didn't really carry over.

Loner T

Level 9

59,471 points

Aug 31, 2014 11:49 AM in response to Redyoshi510

Yes, I meant text. 😉

The reason you cannot see Windows with the Alt key is because the 4th entry in the MBR does not exist. It should show up in Finder though because you have the GPT #4. Can you check?

The MBR #4 needs to be created using

sudo fdisk -e /dev/disk0

edit 4

196993024 (needs to match GPT#4 start)

291403769 (needs to match GPT#4 size)

flag 4

Redyoshi510 Author

Level 1

1 points

Aug 31, 2014 11:00 PM in response to Loner T

After '07':

Do you wish to edit this in CHS mode? [n]

Loner T

Level 9

59,471 points

Sep 1, 2014 5:11 AM in response to Redyoshi510

Use the default, which is 'n'.

Redyoshi510 Author

Level 1

1 points

Sep 1, 2014 8:55 AM in response to Loner T

After typing the 'w', terminal displayed "Device could not be accessed exclusively" before asking me to reboot. Will this be a problem at all? I have not yet rebooted.

Loner T

Level 9

59,471 points

Sep 1, 2014 9:21 AM in response to Redyoshi510

The message is because you rising the same disk for booting as well. It should be safe to reboot.

1. Use the Alt key to check if you can see windows, but do not boot from it yet.

2. In OSX check if the Bootcamp volume is mounted and if you can see files.

3. If #2 works, use System Preferences -> Startup Disk and choose Windows. You may need startup repair if you see a hanging underline cursor at the top left corner.

Redyoshi510 Author

Level 1

1 points

Sep 1, 2014 10:02 AM in response to Loner T

It works now! Thank you very much for your time helping me.

Loner T

Level 9

59,471 points

Sep 1, 2014 10:10 AM in response to Redyoshi510

😎

Oct 22, 2014 8:08 AM in response to Redyoshi510

Hey Redyoshi510, i did the same as you but when i used Mini-Tool Partition Wizard and extruded the space on my windows 7 partition, it asked to restart the pc and then ocurred this error http://imgur.com/TW05ZZw

and my keyboard doesnt work, so im stuck here i dont even know how to get back to osx now. Would really love if you could assist me, or anyone. Thanks

I can't boot to Windows after resizing my Mac partition.