Cant run High Sierra after Bootcamp windows 10 installation

Question

Hi Guys,I ran into trouble yesterdayI own a late 2012 Mac book pro, I have an SSD with High Sierra on it and HDD in optical drive bay which had an older Yosemite OS installed but I wasnt using that anymore.I installed Windows 10 yesterday using Bootcamp, all went smoothly apart from I formatted BOOTCAMP partition to NTFS when asked during windows installation.After setting up windows when I tried to boot into High Sierra, It could not. On OS selection screen at startup it was showing Windows and Yosemite OS but not the High Sierra which is on SSD drive.I tried to access the SSD drive from Yosemite but It didnt shows in Finder and when I tried disk utility it is greyed out and I am not able to mount it.I tried Internet recovery and same happened.Unfortunately I didnt backup anything from High Sierra SSD before installing Windows 10 and I have really really important files on it. I cant risk reformatting and reinstalling as I wil lose my data.I upgraded Yosemite to High Sierra as well but no luck.My question is. Is there any way I can mount or access the hidden partition (appearing as disk0s2 in disk utility) by unconventional method?Any help will be greatly appreciated.

Loner T · Answer

There is no &#x27;unconventional&#x27; method that will help you.First, disconnect the HDD in the Optibay from the Logic Board, otherwise it will just cause more problems.Second, install High Sierra with latest updates on an external disk, and boot from it.Once you are booted in HS, post the output of diskutil listBe aware that your hardware configuration is not officially supported.

Asim.C · Answer

I actually did work around and searching on internet I found this post with semi similar situationdisk utility - Partition type suddenly FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF, drive unmountable - Ask DifferentFollowing the instructions I unmounted, removed and then re-added partitions by entering these codes.Asims-MacBook-Pro:~ asim$ diskutil info /dev/disk1   Device Identifier:        disk1   Device Node:              /dev/disk1   Whole:                    Yes   Part of Whole:            disk1   Device / Media Name:      Ultra    Volume Name:              Not applicable (no file system)   Mounted:                  Not applicable (no file system)   File System:              None    Content (IOContent):      GUID_partition_scheme   OS Can Be Installed:      No   Media Type:               Generic   Protocol:                 USB   SMART Status:             Not Supported    Disk Size:                62.1 GB (62109253632 Bytes) (exactly 121307136 512-Byte-Units)   Device Block Size:        512 Bytes    Read-Only Media:          No   Read-Only Volume:         Not applicable (no file system)    Device Location:          External   Removable Media:          Removable   Media Removal:            Software-Activated    Virtual:                  No   OS 9 Drivers:             No   Low Level Format:         Not supported Asims-MacBook-Pro:~ asim$ sudo gpt remove -i 2 /dev/disk0Password:gpt remove: unable to open device &#x27;/dev/disk0&#x27;: Resource busyAsims-MacBook-Pro:~ asim$ diskutil umountDisk /dev/disk0Unmount of all volumes on disk0 was successfulAsims-MacBook-Pro:~ asim$ udo gpt remove -i 2 /dev/disk0-bash: udo: command not foundAsims-MacBook-Pro:~ asim$ sudo gpt remove -i 2 /dev/disk0/dev/disk0s2 removedAsims-MacBook-Pro:~ asim$ sudo gpt remove -i 3 /dev/disk0gpt remove: unable to open device &#x27;/dev/disk0&#x27;: Resource busyAsims-MacBook-Pro:~ asim$ sudo gpt remove -i 3 /dev/disk0gpt remove: unable to open device &#x27;/dev/disk0&#x27;: Resource busyAsims-MacBook-Pro:~ asim$ diskutil umountDisk /dev/disk0Unmount of all volumes on disk0 was successfulAsims-MacBook-Pro:~ asim$ sudo gpt remove -i 3 /dev/disk0/dev/disk0s3 removedAsims-MacBook-Pro:~ asim$ sudo gpt -r show /dev/disk0      start       sizeindexcontents          0          1         PMBR          1          1         Pri GPT header          2         32         Pri GPT table         34          6                  40     409600      1GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B     409640468452455         468862095         32         Sec GPT table468862127          1         Sec GPT headerAsims-MacBook-Pro:~ asim$ sudo gpt add -b 409640 -i 2 -s 330078112 -t 7C3457EF-0000-11AA-AA11-00306543ECAC /dev/disk0/dev/disk0s2 addedAsims-MacBook-Pro:~ asim$ diskutil umountDisk /dev/disk0Unmount of all volumes on disk0 was successfulAsims-MacBook-Pro:~ asim$ sudo gpt add -b 330487808 -i 3 -s 138373120 -t EBD0A0A2-B9E5-4433-87C0-68B6B72699C7 /dev/disk0Password:/dev/disk0s3 addedAsims-MacBook-Pro:~ asim$ diskutil mountDisk /dev/disk0Volume(s) mounted successfullyAsims-MacBook-Pro:~ asim$After that I was able to see SSD partition and succesfuly booted into my original High Sierra (Phew)But My disk now looks very strange with all the partitions and I am no longer able to see and boot into windows 10 using bootcamp.My current diskutil list isAsims-MacBook-Pro:~ asimchughtai$ diskutil list/dev/disk0 (internal, physical):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *240.1 GB disk0   1:                        EFI EFI                     209.7 MB disk0s1   2:                 Apple_APFS Container disk1         169.0 GB disk0s2   3:       Microsoft Basic Data BOOTCAMP                70.8 GB    disk0s3 /dev/disk1 (synthesized):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      APFS Container Scheme -                      +169.0 GB disk1                                 Physical Store disk0s2   1:                APFS Volume Macintosh HD SSD        108.6 GB disk1s1   2:                APFS Volume Preboot                 20.3 MB    disk1s2   3:                APFS Volume Recovery                520.8 MB disk1s3   4:                APFS Volume VM                      1.1 GB     disk1s4 /dev/disk2 (external, physical):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *62.1 GB    disk2   1:                        EFI EFI                     209.7 MB disk2s1   2:                  Apple_HFS High Sierra             61.2 GB    disk2s2   3:                 Apple_Boot Recovery HD             650.0 MB disk2s3 Asims-MacBook-Pro:~ asimchughtai$ diskutil list/dev/disk0 (internal, physical):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *240.1 GB disk0   1:                        EFI EFI                     209.7 MB disk0s1   2:                 Apple_APFS Container disk1         169.0 GB disk0s2   3:       Microsoft Basic Data BOOTCAMP                70.8 GB    disk0s3 /dev/disk1 (synthesized):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      APFS Container Scheme -                      +169.0 GB disk1                                 Physical Store disk0s2   1:                APFS Volume Macintosh HD SSD        108.5 GB disk1s1   2:                APFS Volume Preboot                 20.3 MB    disk1s2   3:                APFS Volume Recovery                520.8 MB disk1s3   4:                APFS Volume VM                      1.1 GB     disk1s4 It has created weird partitions now which is probably because I messed around.Is there any way I can use Bootcamp partition for Windows 10 I think it is not bootable anymore....Any Suggestion??

Loner T · Answer

You cannot repair Bootcamp using macOS Disk Utility. It requires booting from a Windows installer to run chkdsk. If Windows 10 was installed on the 2012 Mac using EFI Boot, it is problematic. Can you re-install Windows?

Asim.C · Answer

Oh I understand..Yes I can re-install Windows. I don&#x27;t have any data on tat partition.Any advise what should I do different this time before or during Windows installation to avoid running into same problem again..?Many Thanks Loner T

Asim.C · Answer

This is how my partitions are. disk0s2 is the one with OSX installed. Its type shows weird FFFFFFF-FFFF..... typeI cant mount it using Terminal

Asim.C · Answer

Thanks Loner T for replyI have unplugged the Optibay and booted from External driveHere is the Disk util resultsPlease have a lookMany Thanks

Loner T · Answer

Post the output of sudo gpt -vv -r show /dev/disk0

Loner T · Answer

Be careful with GPT commands. If you do not create the correct GPT, you can lose data. Did you run repairDisk?

Asim.C · Answer

I tried but for BOOTCAMP partition first aid  button greys out...

Loner T · Answer

Install Windows fully, before you re-connect the Optibay disk. Do not use EFI Boot on a 2012 Mac.