Windows 10: mbr2gpt Failed - (Disk Layout validation failed for disk 1)

I am trying to change my BIOS from Legacy to UEFI mode. This is necessary in order to have support for storage devices of greater than 2TB capacity and for getting an SSD Card (PCIe) to work.

My hp Z620 Workstation is running Windows 10, version 1809. It has two disk drives in it. The "System" Volume is on Disk 0 (a 500GB Disk Drive), and the OS and "Boot" Volume is on Disk 1 (a 1.0 TB Disk Drive). Disk 0 has only one volume - the entire disk. Disk 1 has two Volumes, the OS/Boot Volume and a data Volume.

To run the tool mbr2gpt.exe ...
I logged off the USER side of Windows and logged into the Administrative side. While in the Administrative side, I brought up the (black colored) Command Window, in Administrative mode. In the Command Window I typed the following:
>mbr2gpt.exe /validate /disk:1 /allowFullOS

I get the following failure: "Disk Layout Validation Failed for Disk 1." When I look into the setuperr and the setupact log files, I get additional information. It says "Validation Layout: Wrong boot partition count, expected 1 but found 0."

Anyone know how to fix this?

I have already researched this quite a bit. For example 'IT Army' has a couple really good videos on youtube, but the solutions do not work for me or do not apply. I have read many forum entries, different sites, to no avail.

I suspect this is the problem, but I don't know for sure: My 'System' Volume and my OS/'Boot' Volume were installed on different hard drives. (The OS was on the system when I bought it).

:)

 

MBR2GPT Not Working (Disk Layout validation failed for disk 1)




It's a custom system, specs below:

Intel 8700k
Gigabyte Auroras Gaming 5 Z370 Motherboard
32 GB Kinston HyperX Ram
Samsung 960 EVO 512 nvme m.2 ssd
1 TB SATA Drive
Gigabyte Auroras Nvidia 1080ti

 

MBR2GPT: Disk layout validation failed for disk 0

When trying to convert to GPT, I get this error:

Here's diskpart info:

And here's a picture of disk management:





I've tried shrinking the storage by a few GB in case it was the issue, but no luck. I'm kinda out of ideas. Maybe the recovery partition counts as a primary partition and thus I go over the 3 primary maximum? It shouldn't, but that's the only idea I have left.

 

MBR2GPT Not Working (Disk Layout validation failed for disk 1)

Hi there, I keep getting this error when trying to convert my system from MBR to GPT.

I had a system made for me (for work) and the company installed my OS in legacy mode... I have two drives, one 512gb NVME Samsung 960 EVO and one Seagate 1 TB disk drive.

I'm booting into command prompt mode (from advanced recovery options) and running the command mbr2gpt /validate /disk:1 .

I had one partition only and even shrunk it by 3 Gigs (unallocated) just to give the tool space (it worked for other users) however I ran into the same issue even after doing that.

Just another note, the 1tb drive (non os) has a System Reserve Partition of 500mb

Any suggestions?