Windows Missing from Boot Screen

Question

Windows Missing from Boot Screen

This thread is started in response to Loner T's advice on this thread: Repairing Boot Camp after creating new partition

I have a hard drive with a partition for Yosemite and an NTFS partition for Windows 10. I just resized the Yosemite partition, and now I can no longer boot into windows as it's not listed on the boot screen when holding "Alt". It does still show up as a boot option in Startup Disk and I can view the contents of the partition. When trying to boot windows from the Startup Disk option, I just get a blinking cursor.

sudo fdisk -e /dev/disk0

p

setpid 4

07

flag 4

p

write

y

Loner T, I'm guessing the above commands will work in my case as well, but would just like to verify before I destroy something. I've posted the output from the commands you requested in the original thread. Thoughts? Thanks in advance!

sh-3.2# fdisk /dev/disk0

Disk: /dev/disk0 geometry: 29185/255/63 [468862128 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 - 193750000] HFS+

3: AB 1023 254 63 - 1023 254 63 [ 194159640 - 1269536] Darwin Boot

4: 0C 1023 254 63 - 1023 254 63 [ 312612864 - 156248064] Win95 FAT32L

sh-3.2# gpt -v -r show /dev/disk0

gpt show: /dev/disk0: mediasize=240057409536; sectorsize=512; blocks=468862128

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

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 193750000 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

194159640 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

195429176 117183688

312612864 156248064 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

468860928 1167

468862095 32 Sec GPT table

468862127 1 Sec GPT header

sh-3.2# diskutil list

/dev/disk0

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *240.1 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS OSX 99.2 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

4: Microsoft Basic Data 80.0 GB disk0s4

/dev/disk1

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *2.0 TB disk1

1: EFI EFI 209.7 MB disk1s1

2: Apple_HFS Storage 2.0 TB disk1s2

/dev/disk2

#: TYPE NAME SIZE IDENTIFIER

0: Apple_partition_scheme *17.2 MB disk2

1: Apple_partition_map 32.3 KB disk2s1

2: Apple_HFS Flash Player 17.1 MB disk2s2

sh-3.2#

Mac Pro, OS X Yosemite (10.10.5)

Posted on Nov 21, 2015 3:24 PM

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Answer 1

Loner T

Level 9

59,513 points

Nov 21, 2015 4:10 PM in response to jdavidlawence

Please post the output of

sudo dd if=/dev/rdisk0s4 count=1 2>/dev/null | hexdump -C

What was the intent behind resizing the Yosemite partition?

Reply

Answer 2

Nov 21, 2015 4:24 PM in response to Loner T

Hi Loner T,

Thanks for the quick reply. I misgauged the amount of size I needed for the Windows partition and ran out of space. I reduced the OS X partition size in order to increase the Windows partition size. Not sure if this is important or evident in the output, but there is now some unallocated space that I plan to use to increase the Windows partition size once I can boot back into it.

Ok, here is the requested output:

sh-3.2# sudo dd if=/dev/rdisk0s4 count=1 2>/dev/null | hexdump -C

00000000 eb 52 90 4e 54 46 53 20 20 20 20 00 02 08 00 00 |.R.NTFS .....|

00000010 00 00 00 00 00 f8 00 00 3f 00 ff 00 00 18 a2 12 |........?.......|

00000020 00 00 00 00 80 00 80 00 ff 17 42 09 00 00 00 00 |..........B.....|

00000030 00 00 0c 00 00 00 00 00 02 00 00 00 00 00 00 00 |................|

00000040 f6 00 00 00 01 00 00 00 fc 13 55 c2 35 55 c2 1c |..........U.5U..|

00000050 00 00 00 00 fa 33 c0 8e d0 bc 00 7c fb 68 c0 07 |.....3.....|.h..|

00000060 1f 1e 68 66 00 cb 88 16 0e 00 66 81 3e 03 00 4e |..hf......f.>..N|

00000070 54 46 53 75 15 b4 41 bb aa 55 cd 13 72 0c 81 fb |TFSu..A..U..r...|

00000080 55 aa 75 06 f7 c1 01 00 75 03 e9 dd 00 1e 83 ec |U.u.....u.......|

00000090 18 68 1a 00 b4 48 8a 16 0e 00 8b f4 16 1f cd 13 |.h...H..........|

000000a0 9f 83 c4 18 9e 58 1f 72 e1 3b 06 0b 00 75 db a3 |.....X.r.;...u..|

000000b0 0f 00 c1 2e 0f 00 04 1e 5a 33 db b9 00 20 2b c8 |........Z3... +.|

000000c0 66 ff 06 11 00 03 16 0f 00 8e c2 ff 06 16 00 e8 |f...............|

000000d0 4b 00 2b c8 77 ef b8 00 bb cd 1a 66 23 c0 75 2d |K.+.w......f#.u-|

000000e0 66 81 fb 54 43 50 41 75 24 81 f9 02 01 72 1e 16 |f..TCPAu$....r..|

000000f0 68 07 bb 16 68 52 11 16 68 09 00 66 53 66 53 66 |h...hR..h..fSfSf|

00000100 55 16 16 16 68 b8 01 66 61 0e 07 cd 1a 33 c0 bf |U...h..fa....3..|

00000110 0a 13 b9 f6 0c fc f3 aa e9 fe 01 90 90 66 60 1e |.............f`.|

00000120 06 66 a1 11 00 66 03 06 1c 00 1e 66 68 00 00 00 |.f...f.....fh...|

00000130 00 66 50 06 53 68 01 00 68 10 00 b4 42 8a 16 0e |.fP.Sh..h...B...|

00000140 00 16 1f 8b f4 cd 13 66 59 5b 5a 66 59 66 59 1f |.......fY[ZfYfY.|

00000150 0f 82 16 00 66 ff 06 11 00 03 16 0f 00 8e c2 ff |....f...........|

00000160 0e 16 00 75 bc 07 1f 66 61 c3 a1 f6 01 e8 09 00 |...u...fa.......|

00000170 a1 fa 01 e8 03 00 f4 eb fd 8b f0 ac 3c 00 74 09 |............<.t.|

00000180 b4 0e bb 07 00 cd 10 eb f2 c3 0d 0a 41 20 64 69 |............A di|

00000190 73 6b 20 72 65 61 64 20 65 72 72 6f 72 20 6f 63 |sk read error oc|

000001a0 63 75 72 72 65 64 00 0d 0a 42 4f 4f 54 4d 47 52 |curred...BOOTMGR|

000001b0 20 69 73 20 63 6f 6d 70 72 65 73 73 65 64 00 0d | is compressed..|

000001c0 0a 50 72 65 73 73 20 43 74 72 6c 2b 41 6c 74 2b |.Press Ctrl+Alt+|

000001d0 44 65 6c 20 74 6f 20 72 65 73 74 61 72 74 0d 0a |Del to restart..|

000001e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

000001f0 00 00 00 00 00 00 8a 01 a7 01 bf 01 00 00 55 aa |..............U.|

00000200

sh-3.2#

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Answer 3

Loner T

Level 9

59,513 points

Nov 21, 2015 5:08 PM in response to jdavidlawence

Try the Fdisk commands. If they do not work, then we are looking at running Testdisk to find the correct partition headers. If the change was resizing OS X (not Windows) then these should work.

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Answer 4

Nov 23, 2015 10:38 AM in response to Loner T

Loner T,

Amazing, that worked! Thanks so much for your help.

Now I just have to figure out how to expand the NTFS partition, which I understand can't be done from OSX. Looks like it's not even possible with the standard windows disk management. I'll look into it further...

Thanks again!

Reply

Answer 5

Loner T

Level 9

59,513 points

Nov 23, 2015 12:38 PM in response to jdavidlawence

You will need to use a Live Linux CD (or any other toolset) and use Gparted to resize the Windows partition. Please ensure you backup all your Windows and OSX data first.

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