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Question mbr2gpt fails (old install, cloned disk)

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wammyrc

Jan 21, 2024
5
0
10
Hi.


I’m trying to convert my primary drive to GPT, but it doesn’t work (the usual Cannot find OS partition).
I’ve looked at everything that crossed my mind, googled and tried a lot of "solutions", but it it just won't budge.

This PC has a long history of Windows upgrades, the original install going back to Vista I think (running Windows 10 22H2 today).
At some point in history, there was a cloning (HDD to SSD), the old HDD now being my secondary drive.
I think this may be the source of the problem (it often is, from what I've read), but I can’t pinpoint why here, everything looks ok to me.
But I'm not expert, at least not on that matter!

I don’t want to go through a reinstallation (I wouldn't post here, otherwise), so I need your help figuring out what’s going on…

Thank you in advance.

Starting with the mbr2gpt output:
Code: 
PS C:\> mbr2gpt /validate /allowFullOS
MBR2GPT: Attempting to validate disk 0
MBR2GPT: Retrieving layout of disk
MBR2GPT: Validating layout, disk sector size is: 512 bytes
Cannot find OS partition(s) for disk 0
In setupact.log, here are the logs generated by the above mbr2gpt attempt:
Code: 
2024-01-21 16:48:18, Info                         MBR2GPT was explicitly asked to run in full OS mode.
2024-01-21 16:48:18, Info                         MBR2GPT: System disk number is 0
2024-01-21 16:48:18, Info                         MBR2GPT: Attempting to validate disk 0
2024-01-21 16:48:18, Info                         MBR2GPT: Retrieving layout of disk
2024-01-21 16:48:18, Info                         MBR2GPT: Initial partition information
2024-01-21 16:48:18, Info                         ===========================================================
2024-01-21 16:48:18, Info                         Partition layout for disk: 0
2024-01-21 16:48:18, Info                         Partition style          : MBR
2024-01-21 16:48:18, Info                         MBR signature: 2384779043
2024-01-21 16:48:18, Info                         Number of partitions     : 3
2024-01-21 16:48:18, Info                         ===================PARTITION===============================
2024-01-21 16:48:18, Info                              Number: 1
2024-01-21 16:48:18, Info                                Type: 7
2024-01-21 16:48:18, Info                                Boot: Yes
2024-01-21 16:48:18, Info                          Recognized: Yes
2024-01-21 16:48:18, Info                               Style: 0
2024-01-21 16:48:18, Info                              Offset: 1048576
2024-01-21 16:48:18, Info                              Length: 586182144
2024-01-21 16:48:18, Info                              Volume: \\?\Volume{d02d0d36-7afb-11e0-ac6d-806e6f6e6963}\
2024-01-21 16:48:18, Info                               Drive: W:\
2024-01-21 16:48:18, Info                             NT Path: \Device\HardDisk0\Partition1
2024-01-21 16:48:18, Info                         ===================PARTITION===============================
2024-01-21 16:48:18, Info                              Number: 2
2024-01-21 16:48:18, Info                                Type: 7
2024-01-21 16:48:18, Info                                Boot: No
2024-01-21 16:48:18, Info                          Recognized: Yes
2024-01-21 16:48:18, Info                               Style: 0
2024-01-21 16:48:18, Info                              Offset: 588251136
2024-01-21 16:48:18, Info                              Length: 999019470848
2024-01-21 16:48:18, Info                              Volume: \\?\Volume{d02d0d37-7afb-11e0-ac6d-806e6f6e6963}\
2024-01-21 16:48:18, Info                               Drive: C:\
2024-01-21 16:48:18, Info                             NT Path: \Device\HardDisk0\Partition2
2024-01-21 16:48:18, Info                         ===================PARTITION===============================
2024-01-21 16:48:18, Info                              Number: 3
2024-01-21 16:48:18, Info                                Type: 7
2024-01-21 16:48:18, Info                                Boot: No
2024-01-21 16:48:18, Info                          Recognized: Yes
2024-01-21 16:48:18, Info                               Style: 0
2024-01-21 16:48:18, Info                              Offset: 999608549376
2024-01-21 16:48:18, Info                              Length: 593389056
2024-01-21 16:48:18, Info                              Volume: \\?\Volume{8e24d723-0000-0000-0000-50bde8000000}\
2024-01-21 16:48:18, Info                               Drive: F:\
2024-01-21 16:48:18, Info                             NT Path: \Device\HardDisk0\Partition3
2024-01-21 16:48:18, Info                         ===========================================================
2024-01-21 16:48:18, Info                         ESP partition size will be 104857600
2024-01-21 16:48:18, Info                         MBR2GPT: Validating layout, disk sector size is: 512 bytes
2024-01-21 16:48:18, Info                         BCD: Opening store. Flags: 0x0
2024-01-21 16:48:18, Info                         BCD: Store path: "\??\GLOBALROOT\device\harddisk0\partition1\Boot\BCD"
2024-01-21 16:48:18, Info                         BCD: Loaded hive at BCD00000000
2024-01-21 16:48:18, Info                         BCD: Opening object {9dea862c-5cdd-4e70-acc1-f32b344d4795}
2024-01-21 16:48:18, Info                         FindOSPartitions: Default boot entry: {8FFCE677-28FC-11EB-B317-9EDFB21876B3}
2024-01-21 16:48:18, Info                         BCD: Opening object {8ffce677-28fc-11eb-b317-9edfb21876b3}
2024-01-21 16:48:18, Info                         VERBOSE: Device path: \Device\HarddiskVolume2
2024-01-21 16:48:18, Info                         VERBOSE: Dos path: \\?\GLOBALROOT\Device\HarddiskVolume2
2024-01-21 16:48:18, Info                         FindOSPartitions: Volume name for the default boot entry: \\?\Volume{d02d0d37-7afb-11e0-ac6d-806e6f6e6963}\
2024-01-21 16:48:18, Info                         BCD: Opening object {f2984748-28fc-11eb-9d2b-fff07c6d5022}
2024-01-21 16:48:18, Info                         VERBOSE: Device path: \Device\HarddiskVolume6
2024-01-21 16:48:18, Info                         VERBOSE: Dos path: \\?\GLOBALROOT\Device\HarddiskVolume6
2024-01-21 16:48:18, Info                         FindOSPartitions: Volume name for the recovery boot entry: \\?\Volume{57f1467a-0000-0000-0000-f08bd1010000}\
2024-01-21 16:48:18, Info                         FindOSPartitions: WIM path for the recovery boot entry: \Recovery\WindowsRE\Winre.wim
2024-01-21 16:48:18, Info                         FindOSPartitions: Default boot entry locale: fr-FR
2024-01-21 16:48:18, Error                        Cannot find OS partition(s) for disk 0

Here’s my setup, drive-wise (apologies for the French language):
akOj3ot.png

As I said earlier, disc#1 was disc#0 in the past, and was cloned into disc#0, hence the two partitions (E: and the 849MB unassigned one), that I never deleted, afraid of breaking something.

That may be important (or irrelevant), but the base user folder (usually C:\Users) is set to G:\Users.

BCD:
Code: 
PS C:\> bcdedit /enum /v

Gestionnaire de démarrage Windows
---------------------------------
identificateur          {9dea862c-5cdd-4e70-acc1-f32b344d4795}
device                  partition=W:
description             Windows Boot Manager
locale                  fr-FR
inherit                 {7ea2e1ac-2e61-4728-aaa3-896d9d0a9f0e}
default                 {8ffce677-28fc-11eb-b317-9edfb21876b3}
resumeobject            {8ffce676-28fc-11eb-b317-9edfb21876b3}
displayorder            {8ffce677-28fc-11eb-b317-9edfb21876b3}
toolsdisplayorder       {b2721d73-1db4-4c62-bf78-c548a880142d}
timeout                 30

Chargeur de démarrage Windows
-----------------------------
identificateur          {8ffce677-28fc-11eb-b317-9edfb21876b3}
device                  partition=C:
path                    \WINDOWS\system32\winload.exe
description             Windows 10
locale                  fr-FR
inherit                 {6efb52bf-1766-41db-a6b3-0ee5eff72bd7}
recoverysequence        {f2984748-28fc-11eb-9d2b-fff07c6d5022}
displaymessageoverride  CommandPrompt
recoveryenabled         Yes
allowedinmemorysettings 0x15000075
osdevice                partition=C:
systemroot              \WINDOWS
resumeobject            {8ffce676-28fc-11eb-b317-9edfb21876b3}
nx                      OptIn
bootmenupolicy          Standard

At some point, BCD was way more complicated, there were a lot of old entries, and the unassigned 849MB partition on disc#1 was designed as Boot Loader (probably a consequence of the cloning process).

I’m not sure when it got cleaner, but it’s probably during one of the the many attempts I tried to make things work.

As I said at the top of this post, I am not willing to reinstall. I’m lazy (well, not that lazy, I wouldn’t be here), but above all, I’m especially very intrigued!

I won’t lie, there’s also some proud in having the same Windows install working for so long. Honestly, this is the only issue I have (and that I ever had, AFAIKR). I’ve put this install through many upgrades, big hardware changes (including switching from intel to AMD), it never seemed to bother. Well, present situation excluded, of course.

So, what shall I run in order to find out why mbr2gpt fails?

Thanks,
wam
 
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Welcome to the forums, newcomer!

You might want to follow through this guide;
https://www.easeus.com/partition-manager-software/free-convert-mbr-to-gpt-without-data-loss.html

I don’t want to go through a reinstallation (I wouldn't post here, otherwise), so I need your help figuring out what’s going on…
Just an FYI, when you post in that nature, you tend to loose most if not all people who want to genuinely help. Yes you're route is actually to reinstall the OS since the upgrade path you went through would mean your license key for Vista>Windows 10 is intact. You can easily source the installer for your OS from Microsoft, for free+takes minutes to install the OS/get the drivers situated.

running Windows 10 22H2 today).
The latest Windows 10 is 23H2, so you're behind on that. Once you see errors in trying to update, assuming you come out through with the partition structure conversion, you will need to reinstall the OS. Best do it in one go.
 
Upvote 0 Downvote
SkyNetRising said:
Delete partition F: and retry by specifying disk number.
mbr2gpt /validate /disk:0 /allowFullOS
mbr2gpt /convert /disk:0 /allowFullOS

BTW - are you sure, your system supports UEFI boot?
If it doesn't, then your system becomes unbootable after the conversion.
Click to expand...
Hi.

Deleted partition F: and retried, specifying disk number, same result:
Code: 
PS C:\> mbr2gpt /validate /disk:0 /allowFullOS
MBR2GPT: Attempting to validate disk 0
MBR2GPT: Retrieving layout of disk
MBR2GPT: Validating layout, disk sector size is: 512 bytes
Cannot find OS partition(s) for disk 0

More in details:
Code: 
2024-01-21 19:05:58, Info                         MBR2GPT was explicitly asked to run in full OS mode.
2024-01-21 19:05:58, Info                         MBR2GPT: Attempting to validate disk 0
2024-01-21 19:05:58, Info                         MBR2GPT: Retrieving layout of disk
2024-01-21 19:05:58, Info                         MBR2GPT: Initial partition information
2024-01-21 19:05:58, Info                         ===========================================================
2024-01-21 19:05:58, Info                         Partition layout for disk: 0
2024-01-21 19:05:58, Info                         Partition style          : MBR
2024-01-21 19:05:58, Info                         MBR signature: 2384779043
2024-01-21 19:05:58, Info                         Number of partitions     : 2
2024-01-21 19:05:58, Info                         ===================PARTITION===============================
2024-01-21 19:05:58, Info                              Number: 1
2024-01-21 19:05:58, Info                                Type: 7
2024-01-21 19:05:58, Info                                Boot: Yes
2024-01-21 19:05:58, Info                          Recognized: Yes
2024-01-21 19:05:58, Info                               Style: 0
2024-01-21 19:05:58, Info                              Offset: 1048576
2024-01-21 19:05:58, Info                              Length: 586182144
2024-01-21 19:05:58, Info                              Volume: \\?\Volume{d02d0d36-7afb-11e0-ac6d-806e6f6e6963}\
2024-01-21 19:05:58, Info                               Drive: W:\
2024-01-21 19:05:58, Info                             NT Path: \Device\HardDisk0\Partition1
2024-01-21 19:05:58, Info                         ===================PARTITION===============================
2024-01-21 19:05:58, Info                              Number: 2
2024-01-21 19:05:58, Info                                Type: 7
2024-01-21 19:05:58, Info                                Boot: No
2024-01-21 19:05:58, Info                          Recognized: Yes
2024-01-21 19:05:58, Info                               Style: 0
2024-01-21 19:05:58, Info                              Offset: 588251136
2024-01-21 19:05:58, Info                              Length: 999019470848
2024-01-21 19:05:58, Info                              Volume: \\?\Volume{d02d0d37-7afb-11e0-ac6d-806e6f6e6963}\
2024-01-21 19:05:58, Info                               Drive: C:\
2024-01-21 19:05:58, Info                             NT Path: \Device\HardDisk0\Partition2
2024-01-21 19:05:58, Info                         ===========================================================
2024-01-21 19:05:58, Info                         ESP partition size will be 104857600
2024-01-21 19:05:58, Info                         MBR2GPT: Validating layout, disk sector size is: 512 bytes
2024-01-21 19:05:58, Info                         BCD: Opening store. Flags: 0x0
2024-01-21 19:05:58, Info                         BCD: Store path: "\??\GLOBALROOT\device\harddisk0\partition1\Boot\BCD"
2024-01-21 19:05:58, Info                         BCD: Loaded hive at BCD00000000
2024-01-21 19:05:58, Info                         BCD: Opening object {9dea862c-5cdd-4e70-acc1-f32b344d4795}
2024-01-21 19:05:58, Info                         FindOSPartitions: Default boot entry: {8FFCE677-28FC-11EB-B317-9EDFB21876B3}
2024-01-21 19:05:58, Info                         BCD: Opening object {8ffce677-28fc-11eb-b317-9edfb21876b3}
2024-01-21 19:05:58, Info                         VERBOSE: Device path: \Device\HarddiskVolume2
2024-01-21 19:05:58, Info                         VERBOSE: Dos path: \\?\GLOBALROOT\Device\HarddiskVolume2
2024-01-21 19:05:58, Info                         FindOSPartitions: Volume name for the default boot entry: \\?\Volume{d02d0d37-7afb-11e0-ac6d-806e6f6e6963}\
2024-01-21 19:05:58, Info                         BCD: Opening object {f2984748-28fc-11eb-9d2b-fff07c6d5022}
2024-01-21 19:05:58, Info                         VERBOSE: Device path: \Device\HarddiskVolume6
2024-01-21 19:05:58, Info                         VERBOSE: Dos path: \\?\GLOBALROOT\Device\HarddiskVolume6
2024-01-21 19:05:58, Info                         FindOSPartitions: Volume name for the recovery boot entry: \\?\Volume{57f1467a-0000-0000-0000-f08bd1010000}\
2024-01-21 19:05:58, Info                         FindOSPartitions: WIM path for the recovery boot entry: \Recovery\WindowsRE\Winre.wim
2024-01-21 19:05:58, Info                         FindOSPartitions: Default boot entry locale: fr-FR
2024-01-21 19:05:58, Error                        Cannot find OS partition(s) for disk 0
 
Upvote 0 Downvote
recovery drive is on disk 1, that can cause issues
you shoul be able to move it to disk 0

open commandline and type in:
diskpart
list disk
select disk 1
list partition
select partition <the-number-of-current-recovery-partition>
assign letter=O
exit

Dism /Capture-Image /ImageFile:C:\recovery-partition.wim /CaptureDir:O:\ /Name:"Recovery"

from your post F: partition is now gone right?, create it again, 566MB might not be enough, you can resize your C: through windows disk management (decrease its size) and increase F: to fit that 850MB you gonna need

once you have your 850MB partition created on disk 0, change drive letter to N

then run those commands:
Dism /Apply-Image /ImageFile:C:\recovery-partition.wim /Index:1 /ApplyDir:N:\
reagentc /disable
reagentc /setreimage /path N:\Recovery\WindowsRE
reagentc /enable
diskpart
select volume N
set id=27
remove

then reboot

after reboot you can delete old unused recovery partition from disk1 which should still have letter O

diskpart
select volume O
delete partition override

now you can try mbr2gpt
 
Last edited:
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Reactions: wammyrc
Upvote 0 Downvote
Lutfij said:
Welcome to the forums, newcomer!
Click to expand...
Thank you!

Lutfij said:
You might want to follow through this guide;
https://www.easeus.com/partition-manager-software/free-convert-mbr-to-gpt-without-data-loss.html
Click to expand...
One of the many articles I read, but I didn't want to launch it without understanding why mbr2gpt doesn't work. The thing is, there is no reason the Windows mbr2gpt fails and a third party app successes.

Like I said, I'm intrigued by the why maybe more than actually converting. For now, of course, because at some point in the future, I will not have a choice... I want to succeed in converting my drive, though, don't get me wrong 😊

Lutfij said:
I don’t want to go through a reinstallation (I wouldn't post here, otherwise), so I need your help figuring out what’s going on…
Just an FYI, when you post in that nature, you tend to loose most if not all people who want to genuinely help. Yes you're route is actually to reinstall the OS since the upgrade path you went through would mean your license key for Vista>Windows 10 is intact. You can easily source the installer for your OS from Microsoft, for free+takes minutes to install the OS/get the drivers situated.
Click to expand...
I don't understand the mindset here... You're telling me that people won't help since I don't want to reinstall?

It's not what I've read here when it comes to issues with mbr2gpt: most of the times, problems were solved without having to reinstall...

Lutfij said:
running Windows 10 22H2 today).
The latest Windows 10 is 23H2, so you're behind on that. Once you see errors in trying to update, assuming you come out through with the partition structure conversion, you will need to reinstall the OS. Best do it in one go.
Click to expand...
23H2 is for Windows 11 only I think, but I can be wrong.
 
Upvote 0 Downvote
kerberos_20 said:
recovery drive is on disk 1, that can cause issues
you shoul be able to move it to disk 0

open commandline and type in:
diskpart
list disk
select disk 1
list partition
select partition <the-number-of-current-recovery-partition>
assign letter=O
exit

Dism /Capture-Image /ImageFile:C:\recovery-partition.wim /CaptureDir:O:\ /Name:"Recovery"

from your post F: partition is now gone right?, create it again, 566MB might not be enough, you can resize your C: through windows disk management (decrease its size) and increase F: to fit that 850MB you gonna need

once you have your 850MB partition created on disk 0, change drive letter to N

then run those commands:
Dism /Apply-Image /ImageFile:C:\recovery-partition.wim /Index:1 /ApplyDir:N:\
reagentc /disable
reagentc /setreimage /path N:\Recovery\WindowsRE
reagentc /enable
diskpart
select volume N
set id=27
remove

then reboot

after reboot you can delete old unused recovery partition from disk1 which should still have letter O

diskpart
select volume O
delete partition override

now you can try mbr2gpt
Click to expand...
Worked like a charm:
Code: 
MBR2GPT: Validation completed successfully

I was so sure the issue had to do with some bad cloning, I disregarded the articles stating the recovery partition on another drive could be the cause of the failure...
Thanks a lot!👍

I'll do the conversion later.

PS: @SkyNetRising mobo supports UEFI, thanks for your concerns!
 
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