MBR2GPT Disk layout validation failed

[Aaron B]

When i try to run 

mbr2gpt /validate /disk:0 /allowFullOS

i get the following output

MBR2GPT: Attempting to validate disk 0
MBR2GPT: Retrieving layout of disk
MBR2GPT: Validating layout, disk sector size is: 512 bytes
Disk layout validation failed for disk 0

I read a bit about it, and it seems to not work because disk 0 isnt a system disk, but in my case it is.

I am using build 1709

[#2]

I got the same error when attempting to use the mbr2gpt tool on my disk0; any ideas what could have caused it?

C:\WINDOWS\system32>mbr2gpt /validate /allowFullOSMBR2GPT:

Attempting to validate disk 0MBR2GPT:

Retrieving layout of diskMBR2GPT:

Validating layout, disk sector size is: 512 bytes

Disk layout validation failed for disk 0

@Aaron B 

[#3]

@Aaron B Boot with   USB windows  10 PE, and then try to enter below command

mbr2gpt.exe /validate /disk:0

mbr2gpt.exe /convert /disk:0

Note once conversion formats all partitions in the Disk 0 , you wont be able  recover anydatas .

for more information, visit below page

**https://docs.microsoft.com/en-us/windows/deployment/mbr-to-gpt**

[#4]

@RAJUMATHEMATICSMSC This is not what i wanted, i wanted to convert the disk while keeping all of my stuff. (See the /allowFullOS switch) 

[#5]

Ill unsubscribe from this because its 2 years old and i no longer require assistance with this.

[#6]

I was facing similar problem as my disk partition was in MBR format but I need it to be GPT format.
Disk validation failed.
Easiest way is solve this problem is as given below.
Go to Disk Manager -> Select disk (0 or 1 ) you want convert and select the partition eg. C -Drive
Right click --> Shrink the disk and put shrink value to 200MB ->OK
Go to CMD with admin mode run the below command
mbr2gpt /validate /disk:0 /allowFullOS -> Enter
Validation is success
Run below command to convert
mbr2gpt /convert /disk:0 /allowFullOS
Disk will be converted to GPT
Go to BIOS and change Legacy to UEFI mode and change boot sequence
Your system will boot with mfg logo

[#7]

I was facing similar problem as my disk partition was in MBR format but I need it to be GPT format.
Disk validation failed.
Easiest way is solve this problem is as given below.
Go to Disk Manager -> Select disk (0 or 1 ) you want convert and select the partition eg. C -Drive
Right click --> Shrink the disk and put shrink value to 200MB ->OK
Go to CMD with admin mode run the below command
mbr2gpt /validate /disk:0 /allowFullOS -> Enter
Validation is success
Run below command to convert
mbr2gpt /convert /disk:0 /allowFullOS
Disk will be converted to GPT
Go to BIOS and change Legacy to UEFI mode and change boot sequence
Your system will boot with mfg logo
NO Data loss

[#8]

I was having this issue, this solved the issue. I shrinked my volume by 2 gb just to be safe.

thanks a bunch!

[#9]

@Palani Samy 

I did not work for me. My system drive is on disk 1 and not disk 0. Maybe that is the reason why.

[#10]

It shouldnt matter which number your disk is. You just need to shrink your system drive. Whether that is disk 0 or 1 or 2 or 3 etc.
Thats the drive you have OS installed on. For me it was disk 3 and my new nvme drive was actually disk 0.

I was changing from sata ssd to nvme ssd. So i copyed the data over to the new drive and then performed the switch on the new drive keeping my original drive as a back up in case some didn't work right on the new one. So far i havent had any issue.

One thing to note is that when you do the conversion, you need to point to the system drive. I believe the end of the convert command you need to type /disk:[system drive] (in your case i guess it will be /disk:1). That will point program to correct drive.

Hope that helps.

[#11]

I am afraid it did not. I used the following command to no avail:
mbr2gpt/disk:1 /validate  /allowFullOS
and I still get that the validation of disk 1 failed.

edit: I also shrank the drive first by 200MB, and then by 2GB, and that did not work either.

[#12]

I think there is issue with you syntax.

It should be

mbr2gpt /validate /disk:1 /allowfullos

There should be a space before each /

Make sure you running command prompt in administrator mode.

[#13]

If it were a matter of syntax, it would have shown. I still did try it out
mbr2gpt /disk:1 /validate /allowFullos

and I started Dos as administrator. I wish someone from MS would react. As grateful as I am for your concern.

edit: according to AOMEI partition assistant, the boot partition and the system partition are on different disks and that I should not convert disk 1. I suppose I'll have to make the system disk as disk 0 to get any further.

I still would like to thank you for your contributions.

[#14]

@Odal53 

i dont think its system partition issue. see the screen shot of my disk 0, which is my converted disk. it has system resevered, os and efi partitions + the 2gb un-allocated space.

can you check and verify if your disk is mbr? I just did a validation and it failed as well. Im wondering if it fails once the drive is already converted to gpt.

Heres link you can follow and try the conversion from preOS environment. its basically the recovery environment.

https://www.windowscentral.com/how-convert-mbr-disk-gpt-move-bios-uefi-windows-10

see if that helps.

[#15]

@Naeem86 

It is MBR. I think the only solution is a back up and a clean installation. When I disable the other boot options, my system drive does not boot. I can set up secure boot and TMP in the bios, but i must reinstall.

[#16]

I have the same problem, but i got it on the HDD with Windows on it, the other 2 doesnt work

[#17]

@Palani Samy 

I have tried this 3 times with 3 fails.

C:\WINDOWS\system32>mbr2gpt /validate /allowfullos
MBR2GPT: Attempting to validate disk 0
MBR2GPT: Retrieving layout of disk
MBR2GPT: Validating layout, disk sector size is: 512 bytes
Disk layout validation failed for disk 0

C:\WINDOWS\system32>mbr2gpt.exe /convert /allowfullos

MBR2GPT will now attempt to convert the default book disk.
If conversion is successful the disk can only be booted in GPT mode.
These changes cannot be undone!

MBR2GPT: Attempting to convert disk 0
MBR2GPT: Retrieving layout of disk
MBR2GPT: Validating layout, disk sector size is: 512 bytes
Disk layout validation failed for disk 0

[#18]

Have you tried doing that from the recovery environment?

I posted a link to instructions on how to do that.

Also, please make sure your windows version is upto date.

[#19]

Yes says I'm up to date. @Naeem86 

[#20]

Please check the actual windows version in system information, dont rely on windows update.

I had a laptop that showed upto date but was runing version 1507. Had to update bios before able to update to latest version.

Also, did you try instructions from the link?