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Bootcamp Windows 7 not working after Yosemite install

I have Windows 7 installed via bootcamp and after installing Yosemite, windows was no longer available via System Preferences>Startup Disk. However, it was still accessible using restart and holding alt/option. Then today I accidentally installed update 10.10.3 and now Windows is completely gone. I do not have a Time Machine Backup and have been scouring these threads for some time trying to piece together a solution to no avail.

I have seen similar threads about this topic however I have not quite found the complete solution to my specific example. Here is some info that should serve usefull to someone willing to help.

diskutil list

/dev/disk0

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *251.0 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS Macintosh HD 186.7 GB disk0s2

3: Microsoft Basic Data 64.0 GB disk0s3

/dev/disk1

#: TYPE NAME SIZE IDENTIFIER

0: FDisk_partition_scheme *4.1 GB disk1

1: DOS_FAT_32 UNTITLED 4.1 GB disk1s1

diskutil cs list

No CoreStorage logical volume groups found

sudo gpt -vv -r show /dev/disk0

gpt show: /dev/disk0: mediasize=251000193024; sectorsize=512; blocks=490234752

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 490234751

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 364564440 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

364974080 262144

365236224 124997632 3 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

490233856 863

490234719 32 Sec GPT table

490234751 1 Sec GPT header

sudo fdisk /dev/disk0

Disk: /dev/disk0 geometry: 30515/255/63 [490234752 sectors]

Signature: 0xAA55

Starting Ending

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

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

1: EE 1023 254 63 - 1023 254 63 [ 1 - 409639] <Unknown ID>

2: AF 1023 254 63 - 1023 254 63 [ 409640 - 364564440] HFS+

3: 0C 1023 254 63 - 1023 254 63 [ 365236224 - 124997632] Win95 FAT32L

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

Also...

I use this computer for work and have a lot of important stuff on the Windows side. Please help.

MacBook Pro with Retina display, OS X Yosemite (10.10.3)

Posted on Apr 13, 2015 5:23 PM

85 replies

J.Amado Author

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Apr 13, 2015 8:51 PM in response to Loner T

Loner T

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Apr 13, 2015 8:58 PM in response to J.Amado

Please reboot. Be aware that we have modified OS X parts, so it may not boot properly. If it does, check if you can see the Bootcamp in Finder. If you cannot boot, then you need to use OS X: About OS X Recovery - Apple Support to re-install OS X. Please ensure that you choose the current GPT2 and do not modify any other partitions. Do not erase the disk.

J.Amado Author

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Apr 13, 2015 9:00 PM in response to Loner T

J.Amado Author

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Apr 13, 2015 9:01 PM in response to Loner T

It looks like it worked. Do I still need to create a Hybrid MBR to boot Windows?

Loner T

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Apr 13, 2015 9:13 PM in response to J.Amado

1. Can you see all your files in Finder?

2. Yes, you do need to recreate the Hybrid MBR. Yours is a special case, so the standard 2 3 4 will not work. You have only 2 and 3. Part 3 (GPT3=MBR3) should be marked bootable.

I am optimistic, it will work. At least you can get all your files, if necessary. I am on the US East coast, and will be gone for a few hours of shut-eye.

J.Amado Author

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Apr 13, 2015 9:12 PM in response to Loner T

J.Amado Author

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Apr 13, 2015 9:14 PM in response to Loner T

Yes all files are there

Loner T

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Apr 13, 2015 9:15 PM in response to J.Amado

I will wait, if you are going to try it now. My suggestion to is to remove personal information from screen shots.

J.Amado Author

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Apr 13, 2015 9:15 PM in response to Loner T

Ok so how do I recreate the Hybrid MBR?

Loner T

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Apr 13, 2015 9:18 PM in response to J.Amado

Rebuild MBR to match the new GPT information thus resetting the Hybrid MBR. Use defaults for other questions (like partition codes). The only values that need modifications are the Boot flags and step 6. Accept all other defaults that Gdisk offers.

Sudo gdisk /dev/disk0
P (Print list of parts)
R (Recover)
H (chooses Hybrid)
Partitions numbers to be hybridized: 2 3
Y (Good for GRUB question)
N (part 2 boot flag)
Y (part 3 boot flag make NTFS bootable partition)
W (Write the new MBR)
Y (Yes! write the new MBR)
Reboot

This is a special case.

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): Press Enter/Return

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

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

Enter an MBR hex code (default 07): Press Enter/Return

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

Test 1 - Does Bootcamp Volume show up in Finder?

Test 2 - Can you see files in Bootcamp Volume?

Test 3 - Can you select Bootcamp in System Preferences -> Startup Disk?

Test 4 - If Test 3 is successful, select Bootcamp and Click Restart.

J.Amado Author

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Apr 13, 2015 9:25 PM in response to Loner T

stuck at this point

Loner T

Level 9

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Apr 13, 2015 9:28 PM in response to J.Amado

You missed step 4. (the 'h' command). Accept the default MBR hex codes.

J.Amado Author

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Apr 13, 2015 9:27 PM in response to Loner T

sorry wasn't reading carefully. here is where I am at

J.Amado Author

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Apr 13, 2015 9:28 PM in response to Loner T

I can't express how much I am appreciating your help. Please hang in this with me a few more minutes.

Loner T

Level 9

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Apr 13, 2015 9:31 PM in response to J.Amado

Type 'N', because there is a large gap between GPT3 and the end of the disk. Make sure you p, w and y the current state. Re-creating the Hybrid MBR is much easier, because it is just a mapping. No partitions are being manipulated.

Bootcamp Windows 7 not working after Yosemite install