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MacTavish_10 Author

Level 1

30 points

Repairing Boot Camp after creating new partition

I'm running OS X 10.9 and Windows 7 x64 Pro.

I set up Boot Camp to dual-boot Windows on my MacBook Pro Retina. Everything was fine. And just yesterday Apple released the Yosemite Beta for the public and I wanted to download this and give it a try. After some research, I found that creating a separate partition was the way to go, and so I made another partition.

I wasn't aware that this would affect my Windows partition as I thought it was completely different.

So now, when I boot up, there is no option to boot with Windows. But when I boot the Mac and select Startup Disk, it shows Boot Camp is still there and all my files etc are still there.

I have a 256SSD, 160GB was for the Mac, and I have 90GB set for Windows.

I made the new partition to 40GB (and the Mac was now 120GB).

Then once I completed that part, I restarted my Mac and the Windows boot option was no longer there.

I didn't even install the Yosemite yet. I went to Disk Utility and deleted the 40GB partition that I made.

Now I don't know what to do. I have a lot of important things which are still on my Windows. Is there a way to restore normal Boot Camp functionality?

MacBook Pro (Retina, 13-inch, Late 2013), OS X Mavericks (10.9.4)

Posted on Jul 25, 2014 8:20 AM

180 replies

Sep 22, 2014 7:33 PM in response to Loner T

Ok i decided to delete all the partitions and only keep Mavericks. Now the problem is when i turn on my Mac it will always try to boot from a non-existent windows partition. How can i solve this?

Using the following menu i don't have any other options beside the Mavericks. I don't understand why it keeps trying to boot from windows, i've to hold Alt key every time.

Loner T

Level 9

59,513 points

Sep 22, 2014 7:57 PM in response to joaomalveiro

Did you use Bootcamp Assistant to remove Windows or was the partition removed via Disk Utility.

Sep 23, 2014 1:38 AM in response to Loner T

i did it using disk utility, didn't occur to me that would be tool to uninstall it 😟

Loner T

Level 9

59,513 points

Sep 23, 2014 4:10 AM in response to joaomalveiro

You need to remove the MBR entries that have Windows. Check the output of sudo disk /dev/disk0.

Sep 23, 2014 4:21 AM in response to Loner T

that command doesn't work :/

jcmm@jcmm ⭕ ~ sudo disk /dev/disk0.

sudo: disk: command not found

Loner T

Level 9

59,513 points

Sep 23, 2014 5:23 AM in response to joaomalveiro

Try sudo fdisk /dev/disk0. (Safari auto-corrected fdisk to disk 😉).

Sep 23, 2014 5:25 AM in response to Loner T

jcmm@jcmm ⭕ ~ sudo fdisk /dev/disk0

Disk: /dev/disk0 geometry: 31130/255/63 [500118192 sectors]

Signature: 0xAA55

Starting Ending

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

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

1: EE 1023 254 63 - 1023 254 63 [ 1 - 500118191] <Unknown ID>

2: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

3: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

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

Loner T

Level 9

59,513 points

Sep 23, 2014 5:35 AM in response to joaomalveiro

Your MBR looks clean. Under System Preferences -> Startup Disk click on OS X and then click on Restart. Test again with a power cycle.

Sep 23, 2014 5:44 AM in response to Loner T

weird.. now i restarted to check it and it's fixed, maybe one random command i entered yesterday before posting my problem here solved the issue. I thought it didn't because it returned an error.

I think this was the one i entered: sudo fdisk -e /dev/disk0.

Loner T

Level 9

59,513 points

Sep 23, 2014 6:00 AM in response to joaomalveiro

This fdisk -e is the interactive mode of fdisk. If you modified the MBR by hand and flagged an entry to be bootable, boot manager will keep picking it up till you change it via System Preferences.

Oct 24, 2014 11:28 AM in response to Loner T

I would be grateful if you could help me.

I have the same issue (i have yosemite 10.10. i partitioned and resized my macintosh hd. and i lost bootcamp start up)

I can see it in my drives. But i lost as startup disk and when i hold down option key there is no windows 7

here are my screen shots:

Loner T

Level 9

59,513 points

Oct 24, 2014 11:33 AM in response to ashmathcom

Can you start a new thread and post images using an external Image sharing website (I use IMGUR, but you use any you want)?

Please remove personal information, if you do not want it visible on a public forum.

Oct 24, 2014 11:46 AM in response to Loner T

Repairing Boot Camp after creating new partition

elyoe011

Level 1

0 points

Nov 24, 2014 5:10 AM in response to Loner T

Loner T,

I did this fix:

sudo fdisk -e /dev/disk0

setpid 4

flag 4

write

When I started Windows all I had was a black screen with a blinking underscore "_"

I went back to my MAC and try it again... but instead of "setpid 4" and "flag 4" I did "setpid 1" and "flag 1"

Now when I boot into Windows/BootCamp is saying "Missing Operating System" and OS X is not bootable.

Also Macintosh HD is gone from Disk Utility when I go into recovery mode and check Disk Utility...

I there any REMEDY for this? I have a lot of data that I need to recover...

ANY help is really appreciated!!!!!!!!

Loner T

Level 9

59,513 points

Nov 24, 2014 5:33 AM in response to elyoe011

Do you want to start a new thread in the Bootcamp Discussions and post the information of the following four commands

diskutil list

diskutil cs list

sudo gpt -vv -r show /dev/disk0

sudo fdisk /dev/disk0

Partition 1 is EFI/ESP is never marked bootable. OSX Bootability is derived from EFI/ESP and the GPT entries. Teh only entry that requires MBR-based bootability is Windows/Bootcamp partition, nothing else.

Repairing Boot Camp after creating new partition