Can't boot from bootcamp after sudden crash

Question

Level 1

0 points

Can't boot from bootcamp after sudden crash

Hi,

So today I was playing cs:go, running bootcamp, when suddenly my mac crashed and rebooted to mavericks... I've tried several things on this thread but I still can't boot on bootcamp... I really need some files I have there and I can't access them -.-' Is there a way to fix this and get bootcamp to work again? Tell me what you need from terminal so I can upload it here.

Btw, when I created the bootcamp partition I created it with 100gb and later I upgraded it to 400gb without reinstalling bootcamp but it as worked fine for more than a month so I'm assuming that is not the problem...

I really need some help with this...

Thanks,

Gabriel

iMac, OS X Mavericks (10.9.2)

Posted on Sep 23, 2014 5:45 PM

Reply

Answer 1

Top-ranking reply

Loner T

Level 9

59,513 points

Sep 23, 2014 6:22 PM in response to fallen002

1. The ~300 GB is sitting right above the GPT#4 entry. Your NTFS header is corrupt.

2. You have two NTFS entries. GPT#4's start/size match the entry #3 in the Fdisk output, but is unbootable (the missing "*").

3. The Fdisk entry #4 has all zeroes and is bootable, but has invalid start/size (0/0).

4. Download GPT Fdisk from SourceForge.net. (http://sourceforge.net/projects/gptfdisk/).

5. Run sudo gdisk /dev/disk0. Delete GPT#4 entry.

6. Add GPT#4 again with start = 1206448520, end=1953525134 (1 before the SEC GPT Table start). You will lose Recovery HD. If you need it, use Command+R to re-install OS X after Windows is functional (not before).

7. In Gdisk, re-create a Hybrid MBR with 2 3 4 (and allow it to add the EFI into the MBR). If you need step-by-step, please post back here.

8. Reboot into OS X.

9. Verify that Bootcamp volume is visible in Finder.

10. Verify that you can see files in Bootcamp volume in Finder.

11. Verify that you can select Bootcamp in System Preferences -> Startup Disk.

12. Select Bootcamp and reboot.

If there are any error messages, please stop and post back here.

Reply

Answer 2

fallen002 Author

Level 1

0 points

Sep 23, 2014 6:33 PM in response to Loner T

Thanks for the help! On step 7. I believe I could use a step-by-step guide just to make sure I don't end up doing something wrong... I'm not sure if I should change the codes or if I should set the bootable flag on all those partitions..

Reply

Answer 3

Loner T

Level 9

59,513 points

Sep 23, 2014 7:01 PM in response to fallen002

7.

sudo gdisk /dev/disk0

type 'r' for Recovery Transformation Menu

type 'h' for Hybrid MBR

Recovery/transformation command (? for help): h

WARNING! Hybrid MBRs are flaky and dangerous! If you decide not to use one,

just hit the Enter key at the below prompt and your MBR partition table will

be untouched.

Type from one to three GPT partition numbers, separated by spaces, to be

added to the hybrid MBR, in sequence: 2 3 4

Place EFI GPT (0xEE) partition first in MBR (good for GRUB)? (Y/N): y

Creating entry for GPT partition #2 (MBR partition #2)

Enter an MBR hex code (default AF):

Set the bootable flag? (Y/N): n

Creating entry for GPT partition #3 (MBR partition #3)

Enter an MBR hex code (default AB):

Set the bootable flag? (Y/N): n

Creating entry for GPT partition #4 (MBR partition #4)

Enter an MBR hex code (default 07):

Set the bootable flag? (Y/N): y

type 'w' to write MBR

type 'y' to confirm the write.

Reply

Answer 4

fallen002 Author

Level 1

0 points

Sep 23, 2014 7:13 PM in response to Loner T

I did all that now but on: "Creating entry for GTP partition #4........" Default MBR hex code says 07 but I have AF... I read somewhere that it needs to be 07 in order to get bootcamp to work.. Do I just have to change it, like typing 07 and it's done?

Thanks once again

Reply

Answer 5

Loner T

Level 9

59,513 points

Sep 23, 2014 7:25 PM in response to fallen002

Partition 2 is AF for OSX.

Partition 3 is AB for Recovery HD

Partition 4 is 07 for Bootcamp. This should also be bootable.

Reply

Answer 6

fallen002 Author

Level 1

0 points

Sep 24, 2014 6:45 AM in response to Loner T

Still can't boot nor see bootcamp on finder nor in System Preferences -> Startup Disk...

Here's what's showing on all the things you asked the first time:

Reply

Answer 7

Loner T

Level 9

59,513 points

Sep 24, 2014 7:38 AM in response to fallen002

1. The GPT does not look correct. It needs to be Microsoft Basic Data (1454211072 499998720 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7). This is why diskutil list showing it as Apple_HFS. You will need to use '07' when the GPT is created, and not use the default of AF.

2. The MBR is correct.

3. The dd command needs to use rdisk0s4 not rdisks0.

Reply

Answer 8

fallen002 Author

Level 1

0 points

Sep 24, 2014 8:12 AM in response to Loner T

Could you please tell me how I can do all that? I'm kinda new to all this so I don't know how I can do that :/

Thanks

Reply

Answer 9

Loner T

Level 9

59,513 points

Sep 24, 2014 8:23 AM in response to fallen002

sudo gdisk /dev/disk0

p

d

4

n

4

(Put the correct Start value here)

(Put the correct End value here)

p

w

y

Now run sudo gpt -vv -r show /dev/disk0 and verify. After a reboot, please verify the OSX Finder can see Bootcamp and files. You can see all available commands by typing '?'.

Reply

Answer 10

fallen002 Author

Level 1

0 points

Sep 24, 2014 8:41 AM in response to Loner T

First sector (34-1953525134, default = 1206448520) or {+-}size{KMGTP}: 1206448520

Last sector (1206448520-1953525134, default = 1953525134) or {+-}size{KMGTP}: 1953525134 Are these the right values?

Current type is 'Apple HFS/HFS+'

Hex code or GUID (L to show codes, Enter = AF00): what should be here?

I didn't change the code because I didn't know if I should but basically in the end it didn't have the right GPT..

Thanks

Reply

Answer 11

Loner T

Level 9

59,513 points

Sep 24, 2014 11:53 AM in response to fallen002

Yes, the values are correct. It should be '07' or '0700'. Either should work.

Reply

Answer 12

fallen002 Author

Level 1

0 points

Sep 24, 2014 3:03 PM in response to Loner T

thanks, I changed the disk to microsoft basic data but still can't boot nor see bootcamp on finder nor in System Preferences -> Startup Disk

Reply

Answer 13

Loner T

Level 9

59,513 points

Sep 24, 2014 3:48 PM in response to fallen002

You have just re-executed step 6. Step 7 is still needed for the Hybrid MBR. As you can see there is no entry 4 in your FDisk output.

Reply

Answer 14

fallen002 Author

Level 1

0 points

Sep 24, 2014 4:22 PM in response to Loner T

did step 6 again and than 7 and still not working 😟 this is so frustrating... because it is supposed to work now -.-'

Reply

Answer 15

Loner T

Level 9

59,513 points

Sep 24, 2014 4:34 PM in response to fallen002

You will need to use Testdisk to find the lost NTFS partition. This should provide the correct start/size since the original guess is not correct. Do you recall the size of your working Windows partition (100GB or 400GB).

You can download it from http://www.cgsecurity.org/wiki/TestDisk and use http://www.cgsecurity.org/wiki/TestDisk_Step_By_Step .

Reply