Level 1

8 points

"Missing Operating System"

I upgraded to High Sierra the other day and noticed my Windows Partition (Win 10) was missing when I held down Alt while starting my MacBook Pro up. I had this problem long ago and created a hybrid MBR to resolve the issue then. Instinctively, I tried again and sure enough, Windows appeared as an option when I turn on the MacBook and hold Alt, but now it says "Missing Operating System." I can boot into Mac OS and Recovery just fine.

I can't see the Bootcamp any longer in Finder, and Disk Utility has it listed as "disk0s4" and it is grayed out. It cannot be mounted or repaired, and it is not an option in Startup Disk.

For convenience sake, attached below is a few commands (diskutil, fdisk, gdisk) from Terminal that are usually requested. I have scoured over the topics on here but I can't seem to crack this.

I'm trying to recover some files that are on the Windows partition, otherwise I would wipe the whole thing and start anew.

Let me know if there's anything to be done - any advice is greatly appreciated.

diskutil list

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *750.2 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS Macintosh HD 549.3 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

4: Microsoft Basic Data 200.0 GB disk0s4

fdisk: 1> p

Disk: /dev/disk0 geometry: 91201/255/63 [1465149168 sectors]

Offset: 0 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 25 127 15 - 1023 254 63 [ 409640 - 1072844984] HFS+

3: AB 1023 254 63 - 1023 254 63 [1073254624 - 1269536] Darwin Boot

*4: 07 1023 254 63 - 1023 254 63 [1074524160 - 390623232] HPFS/QNX/AUX

sudo gdisk /dev/disk0

Disk /dev/disk0: 1465149168 sectors, 698.6 GiB

Sector size (logical): 512 bytes

Disk identifier (GUID): E3631DF3-C36F-48BA-9F75-769D070772A1

Partition table holds up to 128 entries

Main partition table begins at sector 2 and ends at sector 33

First usable sector is 34, last usable sector is 1465149134

Partitions will be aligned on 8-sector boundaries

Total free space is 1749 sectors (874.5 KiB)

Number Start (sector) End (sector) Size Code Name

1 40 409639 200.0 MiB EF00 EFI System Partition

2 409640 1073254623 511.6 GiB AF00 Customer

3 1073254624 1074524159 619.9 MiB AB00

4 1074524160 1465147391 186.3 GiB 0700 BOOTCAMP

Posted on Feb 17, 2018 5:36 PM

Similar questions

58 replies

Birdman688 Author

Level 1

8 points

Feb 19, 2018 2:39 PM in response to Loner T

As far as having any third-party NTFS software, I don't to my knowledge.

Here's the two outputs:

diskutil list

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *750.2 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS Macintosh HD 450.0 GB disk0s2

3: Microsoft Basic Data 299.9 GB disk0s3

/dev/disk1 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *500.1 GB disk1

1: EFI EFI 209.7 MB disk1s1

2: Apple_HFS OS X 499.2 GB disk1s2

3: Apple_Boot Recovery HD 650.0 MB disk1s3

sudo gpt -vv -r show /dev/disk0

Password:

gpt show: /dev/disk0: mediasize=750156374016; sectorsize=512; blocks=1465149168

gpt show: /dev/disk0: PMBR at sector 0

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

gpt show: /dev/disk0: Sec GPT at sector 1465149167

start size index contents

0 1 PMBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 878907352 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

879316992 585830393 3 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

1465147385 1750

1465149135 32 Sec GPT table

1465149167 1 Sec GPT header

Birdman688 Author

Level 1

8 points

Feb 19, 2018 2:53 PM in response to Loner T

Nothing seems to happen when attempting to mount disk0s3 in Disk Utility. Here is the output for the hexdump:

sudo dd if=/dev/rdisk0s3 count=1 2>/dev/null | hexdump -C

Password:

00000000 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a |ZZZZZZZZZZZZZZZZ|

00000200

Birdman688 Author

Level 1

8 points

Feb 19, 2018 3:17 PM in response to Loner T

Understood. I am running Testdisk again and will screenshot before selecting anything once the scan is complete.

Your dedication and patience with this is truly appreciated - I will give an update as soon as the analysis finishes.

Birdman688 Author

Level 1

8 points

Feb 19, 2018 4:34 PM in response to Loner T

Update - Testdisk has completed; here are two screenshots:

First page - as before, I hit enter to continue on.

To this page:

This time, I have not moved to [BOOTCAMP]. I will await further instruction on this screen. Thanks!

Birdman688 Author

Level 1

8 points

Feb 19, 2018 6:50 PM in response to Loner T

During this process at some point, the Mackintosh HD reappeared in my Finder window while booted up via external HD. Previously, I had copied everything off of that partition onto another external HD, so everything is backed up and fine there (only data I cannot access now is in the Boot Camp Partition). I have NOT tried to boot into High Sierra via the internal HD since this reappeared, but I certainly can try if it will help anything.

I don't have a Windows 10 CD (it was upgraded maybe a year ago through Microsoft's website), but I did recently download a Windows 10 .iso. My CD drive doesn't seem to be taking CDs (another problem? potentially unrelated - I have not used the drive in so long I had no idea). I can get a Windows 10 CD in the next few days but now I'm unsure that it will stay in the CD drive, as it keeps spitting discs out.

It's a problem on top of a problem for sure, but is there a good way you recommend maybe putting the Windows .iso on a hard drive via Mac and booting from that? Similar to how the computer is running now?

Just spitballing, let me know about trying to boot internally and what you recommend for getting Windows recovery going. Thanks as always!

Loner T

Level 9

59,536 points

Feb 19, 2018 6:57 PM in response to Birdman688

Your Optical drive is problematic based on your description and the issues you have encountered with it so far.

One more option to consider is to import the current Bootcamp partition into a VMware Fusion VM and check if it can be repaired as a VM. If it can, then it will also boot under Bootcamp, after a successful repair.

Birdman688 Author

Level 1

8 points

Feb 19, 2018 7:29 PM in response to Loner T

I just successfully booted into High Sierra on the internal HD. Should I try VMWare Fusion? I have never used it but am willing to learn. I have downloaded the trial - do I just need to install the .iso I have for Windows 10? It couldn't find Boot Camp partition (understandable given it's currently hidden/unmounted):

Is VMWare Fusion still an option to install the Windows 10 .iso I have to? If so, could you walk me through how we can get the chkdsk running for the missing Boot Camp partition?

Thank you so much!

Birdman688 Author

Level 1

8 points

Feb 20, 2018 7:46 AM in response to Loner T

I've finished the procedure as instructed - I once again see "Windows" as a partition when I boot up the computer and hold Alt, but it still says "Missing Operating System." The Boot Camp partition is also not there in Finder.

Birdman688 Author

Level 1

8 points

Feb 20, 2018 11:36 AM in response to Loner T

Later today I can borrow a MacBook Air if need be, and I do have VMWare Fusion installed on my MacBook Pro's internal HD now, although I have not tried installing the Windows 10 .iso.

Let me know what you'd like me to try!

Birdman688 Author

Level 1

8 points

Feb 17, 2018 6:06 PM in response to Loner T

I have followed along with that thread and am currently running Testdisk.

I understand it may take a while - I will update you when it is completed.

Thanks again!

Birdman688 Author

Level 1

8 points

Feb 17, 2018 8:20 PM in response to Loner T

The Testdesk has just completed - there are three (not sure why) MS Data partitions listed.

Is there one specifically I should be looking out for? Any help on how to proceed is greatly appreciated!

Loner T

Level 9

59,536 points

Feb 18, 2018 5:02 AM in response to Birdman688

This is a list of unrecoverable partitions. Press Return/Enter to continue and you will see a list of viable partitions.

Loner T

Level 9

59,536 points

Feb 18, 2018 6:41 PM in response to Birdman688

Do you have the same version of macOS that is on your internal disk, also installed on an external disk?

Birdman688 Author

Level 1

8 points

Feb 19, 2018 5:06 PM in response to Loner T

Okay, went to the entry below:

Unsure why this (near) duplicate was here; let me know if you need me to check any others.

Birdman688 Author

Level 1

8 points

Feb 19, 2018 5:22 PM in response to Loner T

Here's a screenshot with [BOOTCAMP] highlighted. No 'p' yet.

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"Missing Operating System"