Stuck on MBR2GPT issue

Question

I wanted to convert my MBR Windows disk to GPT because I cannot upgrade to later Windows versions. Found the in-place upgrade tool (mbr2gpt) but running into multiple problems.

This is my Disk management layout:

Steps Taken to convert:

When I run the command line tool MBR2GPT.EXE /convert /allowFullOS it gives me the error: "Cannot find OS partition(s) for disk 0
Afterwards I tried to mount a drive letter to my windows partition in order to find corrupt bcd data using this tutorial: https://www.youtube.com/watch?v=E2a5Uqj02OM&list=WL&index=1&ab_channel=NehalJWani However when trying to mount a drive letter to my partition I get a virtual disk service error

I'm quite stumped how to proceed at this moment. Underneath, I'll post the setuperr.log + setupact.log + some extra info / actions I already tried. I would be very grateful if a good soul here could point me in the correct direction :)

Various steps tried + other info:

restart virtual disk service + set it to automatic
remove my swap file on my windows drive
shrink my C: drive
If I check my bios secure boot is on and CSM is already disabled. I find this very strange. Could it be that my system is already in UEFI with an MBR style disk? Some other bios screenshots: https://i.stack.imgur.com/96E0q.jpg
I'm on Windows 1903 Home edition
I have not tried to use mbr2gpt yet in recovery console (yet)

edit

It appears to be that my bios mode already is in UEFI mode as msinfo32 indicates that my bios is in UEFI. However my disk in diskmgmt show up as MBR. This leaves me to the conclusion that my system is in UEFI/MBR

setuperr.log:


2022-11-02 20:07:02, Error                        FindOSPartitions: Cannot open BCD for boot volume. Error: 0xC000000F
2022-11-02 20:07:02, Error                        Cannot find OS partition(s) for disk 0
2022-11-02 20:16:57, Error                        FindOSPartitions: Cannot open BCD for boot volume. Error: 0xC000000F
2022-11-02 20:16:57, Error                        Cannot find OS partition(s) for disk 0
2022-11-04 08:59:30, Error                        FindOSPartitions: Cannot open BCD for boot volume. Error: 0xC000000F
2022-11-04 08:59:30, Error                        Cannot find OS partition(s) for disk 0
2022-11-04 09:32:26, Error                        FindOSPartitions: Cannot open BCD for boot volume. Error: 0xC000000F
2022-11-04 09:32:26, Error                        Cannot find OS partition(s) for disk 0

Setupact.log

2022-11-04 09:32:26, Info                         MBR2GPT was explicitly asked to run in full OS mode.
2022-11-04 09:32:26, Info                         MBR2GPT: System disk number is 0
2022-11-04 09:32:26, Info                         MBR2GPT: Attempting to convert disk 0
2022-11-04 09:32:26, Info                         MBR2GPT: Retrieving layout of disk
2022-11-04 09:32:26, Info                         MBR2GPT: Initial partition information
2022-11-04 09:32:26, Info                         ===========================================================
2022-11-04 09:32:26, Info                         Partition layout for disk: 0
2022-11-04 09:32:26, Info                         Partition style          : MBR
2022-11-04 09:32:26, Info                         MBR signature: 2928498858
2022-11-04 09:32:26, Info                         Number of partitions     : 2
2022-11-04 09:32:26, Info                         ===================PARTITION===============================
2022-11-04 09:32:26, Info                              Number: 1
2022-11-04 09:32:26, Info                                Type: 7
2022-11-04 09:32:26, Info                                Boot: Yes
2022-11-04 09:32:26, Info                          Recognized: Yes
2022-11-04 09:32:26, Info                               Style: 0
2022-11-04 09:32:26, Info                              Offset: 1048576
2022-11-04 09:32:26, Info                              Length: 894715273728
2022-11-04 09:32:26, Info                              Volume: \\?\Volume{ae8d58aa-0000-0000-0000-100000000000}\
2022-11-04 09:32:26, Info                               Drive: C:\
2022-11-04 09:32:26, Info                             NT Path: \Device\HardDisk0\Partition1
2022-11-04 09:32:26, Info                         ===================PARTITION===============================
2022-11-04 09:32:26, Info                              Number: 2
2022-11-04 09:32:26, Info                                Type: 39
2022-11-04 09:32:26, Info                                Boot: No
2022-11-04 09:32:26, Info                          Recognized: Yes
2022-11-04 09:32:26, Info                               Style: 0
2022-11-04 09:32:26, Info                              Offset: 999654686720
2022-11-04 09:32:26, Info                              Length: 547356672
2022-11-04 09:32:26, Info                              Volume: \\?\Volume{ae8d58aa-0000-0000-0000-10c0e8000000}\
2022-11-04 09:32:26, Info                               Drive: None
2022-11-04 09:32:26, Info                             NT Path: \Device\HardDisk0\Partition2
2022-11-04 09:32:26, Info                         ===========================================================
2022-11-04 09:32:26, Info                         ESP partition size will be 104857600
2022-11-04 09:32:26, Info                         MBR2GPT: Validating layout, disk sector size is: 512 bytes
2022-11-04 09:32:26, Info                         BCD: Opening store. Flags: 0x0
2022-11-04 09:32:26, Info                         BCD: Store path: "\??\GLOBALROOT\device\harddisk0\partition1\Boot\BCD"
2022-11-04 09:32:26, Info                         BCD: Failed to load hive into key BCD00000000 from \??\GLOBALROOT\device\harddisk0\partition1\Boot\BCD. Status: c000000f
2022-11-04 09:32:26, Info                         BCD: BcdOpenStore: Failed to add store from file \??\GLOBALROOT\device\harddisk0\partition1\Boot\BCD. StoreFlags: 0x0 Status: c000000f
2022-11-04 09:32:26, Error                        FindOSPartitions: Cannot open BCD for boot volume. Error: 0xC000000F
2022-11-04 09:32:26, Error                        Cannot find OS partition(s) for disk 0
2022-11-04 09:32:26, Info                         MBR2GPT: Partition information at error point
2022-11-04 09:32:26, Info                         ===========================================================
2022-11-04 09:32:26, Info                         Partition layout for disk: 0
2022-11-04 09:32:26, Info                         Partition style          : MBR
2022-11-04 09:32:26, Info                         MBR signature: 2928498858
2022-11-04 09:32:26, Info                         Number of partitions     : 2
2022-11-04 09:32:26, Info                         ===================PARTITION===============================
2022-11-04 09:32:26, Info                              Number: 1
2022-11-04 09:32:26, Info                                Type: 7
2022-11-04 09:32:26, Info                                Boot: Yes
2022-11-04 09:32:26, Info                          Recognized: Yes
2022-11-04 09:32:26, Info                               Style: 0
2022-11-04 09:32:26, Info                              Offset: 1048576
2022-11-04 09:32:26, Info                              Length: 894715273728
2022-11-04 09:32:26, Info                              Volume: \\?\Volume{ae8d58aa-0000-0000-0000-100000000000}\
2022-11-04 09:32:26, Info                               Drive: C:\
2022-11-04 09:32:26, Info                             NT Path: \Device\HardDisk0\Partition1
2022-11-04 09:32:26, Info                         ===================PARTITION===============================
2022-11-04 09:32:26, Info                              Number: 2
2022-11-04 09:32:26, Info                                Type: 39
2022-11-04 09:32:26, Info                                Boot: No
2022-11-04 09:32:26, Info                          Recognized: Yes
2022-11-04 09:32:26, Info                               Style: 0
2022-11-04 09:32:26, Info                              Offset: 999654686720
2022-11-04 09:32:26, Info                              Length: 547356672
2022-11-04 09:32:26, Info                              Volume: \\?\Volume{ae8d58aa-0000-0000-0000-10c0e8000000}\
2022-11-04 09:32:26, Info                               Drive: None
2022-11-04 09:32:26, Info                             NT Path: \Device\HardDisk0\Partition2
2022-11-04 09:32:26, Info                         ===========================================================
2022-11-04 09:32:26, Info                         MBR2GPT: Conversion failed

bcedit /enum firmware

C:\windows\system32>bcdedit /enum firmware
Firmware Boot Manager
identifier              {fwbootmgr}
displayorder            {bootmgr}
                        {ac07aa28-6f71-11ea-8bf8-806e6f6e6963}
                        {ac07aa29-6f71-11ea-8bf8-806e6f6e6963}
                        {0d46b7bc-5c18-11ed-8f77-806e6f6e6963}
                        {0d46b7bd-5c18-11ed-8f77-806e6f6e6963}
                        {0d46b7be-5c18-11ed-8f77-806e6f6e6963}
timeout                 1
Windows Boot Manager
identifier              {bootmgr}
device                  partition=C:
path                    \EFI\MICROSOFT\BOOT\BOOTMGFW.EFI
description             Windows Boot Manager
locale                  en-us
inherit                 {globalsettings}
default                 {current}
resumeobject            {ceda587d-5560-11ea-a58b-9646dbae1b76}
displayorder            {current}
toolsdisplayorder       {memdiag}
timeout                 30
Firmware Application (101fffff)
identifier              {0d46b7bc-5c18-11ed-8f77-806e6f6e6963}
description             UEFI:CD/DVD Drive
Firmware Application (101fffff)
identifier              {0d46b7bd-5c18-11ed-8f77-806e6f6e6963}
description             UEFI:Removable Device
Firmware Application (101fffff)
identifier              {0d46b7be-5c18-11ed-8f77-806e6f6e6963}
description             UEFI:Network Device
Firmware Application (101fffff)
identifier              {ac07aa28-6f71-11ea-8bf8-806e6f6e6963}
description             UEFI: PXE IP4 Intel(R) Ethernet Connection (7) I219-V
Firmware Application (101fffff)
identifier              {ac07aa29-6f71-11ea-8bf8-806e6f6e6963}
description             UEFI: PXE IP6 Intel(R) Ethernet Connection (7) I219-V

Let me know if extra info should be needed :) Have a nice day everyone!

Is there an C:\EFI\Microsoft directory? What do you get from bcdedit /enum firmware? — u1686_grawity, Nov 04 '22 at 09:27
thank you for the help, I have a C:\EFI\Microsoft directory, I have added the bcedit to the original post :) — InSr33, Nov 04 '22 at 10:51
If you already have Secure Boot enabled, and Windows will boot, your disk is already GPT. Additionally, if you already have an EFI directory, that also means Windows was installed in UEFI and not Legacy mode. Your inability to update Windows has nothing to do with Legacy or UEFI mode based on those logs. — Ramhound, Nov 04 '22 at 11:37
I'm even more confused now :) If I check msinfo32 my bios mode is also listed as "UEFI". However in computer management my partition style is indicated as "MBR" I came across another thread which mentioned booting in UEFI/MBR (which seems to be the case for me) The user got it solved by using this command: bcdboot c:\Windows /f bios /s Could this be my solution? Original thread: https://superuser.com/questions/1218991/how-can-i-solve-this-mbr2gpt-issue — InSr33, Nov 04 '22 at 12:24

score 0 · Answer 1 · answered Nov 04 '22 at 09:41

You will find more information in the article Best Way to Fix “MBR2GPT Cannot Find OS Partition” in Windows 10, but one remark is that assigning a drive-letter should be done to both the Windows partition and the system reserved partition.

But as this method is complicated and dangerous in case of an error, the article recommends using the third-party free utility AOMEI Partition Assistant Standard.

Note that you should ensure that your BIOS is of the EFI type, or this conversion will make your disk unbootable. After the conversion, you might need to tweak some BIOS parameters and might also need to do a Startup Repair of Windows (so also prepare yourself a boot USB media for Windows).

Note that it's better to take good backups before doing this conversion, as any error will render your computer unbootable. I also suggest taking an image backup of the entire disk, with for example AOMEI Backupper Freeware, as well as to create and test its boot media, for being able to return your disk to its previous condition, if the worst happens.

Reference : Microsoft's MBR2GPT.EXE.

thank you very much harrymc for the detailed info! Much appreciated. I already made an image of my windows disk using Acronis. I found for my motherboard model (Asus Maximus Xi Code) that I needed to disable CSM and changing Secure Boot to WinUEFI mode. I have a windows 10 boot stick available in case it goes wrong :) — InSr33, Nov 04 '22 at 10:44

Stuck on MBR2GPT issue

Firmware Boot Manager

Windows Boot Manager

Firmware Application (101fffff)

Firmware Application (101fffff)

Firmware Application (101fffff)

Firmware Application (101fffff)

Firmware Application (101fffff)

1 Answers1