Forum Discussion
MBR2GPT Disk layout validation failed
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
109 Replies
Watch this video. https://youtu.be/ytRJhwL6vAg
Rasel2500 has provided an answer that most people - including most in this thread (from everything I've read in the entire thread) - overlooked.
Watching the video provided a VERY good answer that the video just glossed over...even though the person in the video just quickly mentioned the logs and where to find them.
Here's the video he posted - Watch this video. https://youtu.be/ytRJhwL6vAg
Read the log reports "after" running \Windows\system32>mbr2gpt /validate /allowfullos in the command prompt as admin.
What "I" found was in the last entry in the log found in C:\Windows\setupact.log
Run mbr2gpt validate again and read the "last" entry, the "last" line in that entry. Here was the entry I found in the last line the last time I got the failure error:
ValidateLayout: Last partition too close to the end of the disk. Should end at offset 1000204869120 or below, found at 1000204886016
What that's saying is the third partition I have was too close to the end of the drive and the size of the volume (partition) needed to be reduced.
I calculated the difference between what was the expected end ("should end at") and the actual end of the partition. Using that number I used "Disk Management" in Win 10 to "Shrink Volume" by the amount of the "difference" between the 2 numbers. (In my case, I needed to shrink the volume by 16,896 MB.)
After I shrank the volume by the specific difference between the 2 log numbers, I ran mbr2gpt /validate one more time.
It passed!
I was then able to use mbr2gpt /convert and the conversion worked!
Nothing was lost (other than a lot of hair), and I checked the system with PC Health and got confirmation - the system requirements for Windows 11 are now met! I can install 11...whenever it's rolled out to my computer...
The "secret" to watching the video wasn't all the steps. The secret was that the video shows you how to look at the log files and see "why" the error message appears, but the guy in the video didn't even say that - he just turned a light bulb on in my head that said to "check the logs".
Check your log entries!
Every time you run mbr2gpt it's logged. Everything that happens when you run that command is detailed in the log.
Comply with the details in the log to correct the error and you are then ready to run mbr2gpt successfully!
Thanks Microsoft for letting us all know there is a critical step to get answers about why our system does not meet the Win 11 requirements.
It's too bad we all have to spend an inordinate amount of time jumping through these hoops. But now you have a "great" way to find a resolve.
Your system may have a different reason the validation failed, but looking at the log entries will tell you the answer to your error.
I hope this makes a lot of people smile after all the frustration they've had.Thank you, finding that log file was the key. I just needed to free up 1024mb of space at the end of the disk. Job done.
- I had the same problem and here's what I did to fix mine problem. in short.
1) The drive must have 3 or less partitions.
2) I believe you need some free space at the end of the drive (guess only, not confirmed)
In my case my system drive happens to have 4 partitions. 2 of which are the recovery partition, one of which was a left behind from prior windows upgrade. I manually removed the unneeded recovery partition which happens to be the last partition in my drive, and leaving my system with only 3 partitions and almost 500M of space at the end.
The reason I 'guess' some space is needed at the end of the drive is because someone else on this thread has mentioned as the shrink their partition, the validation started working, and as my reading on GPT goes, it suggest GPT does write a backup partition table at the end of the drive. The space required should be very tiny IMO, but no space at all could 'maybe' a cause of the problem?- I tried shrinking the drive as suggested in other posts by 200mb and 2gb then running the command again. Making those changes did not help I still got the same error.
Please go throw the below steps:
- There should be a maximum of three primary partitions in the MBR partition table, including 100MB system partition as mentioned below:
1. (System, Active, Primary Partition)
2. C: (Boot, Page File, Cash Dumps, Primary Partition)
3. 😧 (Primary Partition) - You should not have any extended/logical partition, all three partitions must be primary partitions.
- If you have more than three partitions, you must delete the least important partitions after backing up the important data.
- I have done it successfully (Screenshot Attached)
mbr2gpt
- SalmanAhmed Outstanding help. Clear and organized. Fixed my problem. Now have my EVO SSD running as a GPT boot drive. Cheers!
Thanks! It worked for me!
Must have 3 or less active partition. (unallocated space is no problem)
Hi YvesVA,
I'm glad that the above information was useful for you. Please do not hesitate to contact me for any further assistance, I will welcome the questions you may have.
- There should be a maximum of three primary partitions in the MBR partition table, including 100MB system partition as mentioned below:
- I faced this issue because my system partition and boot partition were different disks
I copied the system partition to the same disk as boot partition, rebooted with bios change to point to correct disk (boot order), then deleted to older system partition on wrong disk.
I was able to run this command successfully after that.
Turned the boot to uefi from legacy
Enabled secure boot and tpm 2
Now I am able to install windows 11. Hope this helps. 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**
@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
The validate command will fail if you run it in a regular Win10 PE (such as AOMEI PA USB boot drive) without manually adding the ReAgent.dll file to the PE environment first ... see Known Issue and Workaround sections of https://docs.microsoft.com/en-us/windows/deployment/mbr-to-gpt#troubleshooting for explanation.
RAJUMATHEMATICSMSC This is not what i wanted, i wanted to convert the disk while keeping all of my stuff. (See the /allowFullOS switch)
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
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
- 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- Thank you for your answer, it has been really helpful!
