Issue with MBR2GPT

[CTRL-ALT-DEFEAT]

Hello

 

I'm having problems moving my Windows 10 Pro installation from Legacy to UEFI and trying to use MBR2GPT to do this (I'm on 1909 for Windows), however, it fails to validate.

 

The OS is installed to a Samsung 970 EVO NVMe M.2 SSD and apparently because this is slotted directly onto the motherboard, Windows reports it as being Disk 2 instead of Disk 0.

 

However, I ran mbr2gpt.exe /validate /disk:2 /logs:C:\Windows /allowFullOS from an elevated command prompt and get the following:

 

MBR2GPT: Attempting to validate disk 2
MBR2GPT: Retrieving layout of disk
MBR2GPT: Validating layout, disk sector size is: 512 bytes
Disk layout validation failed for disk 2

 

I checked the log and get the following from that:

 

2020-04-18 22:09:52, Error                        ValidateLayout: Wrong boot partition count, expected 1 but found 0.
2020-04-18 22:09:52, Error                        Disk layout validation failed for disk 2

 

I am stuck at this point and unsure how to get this to validate so I can make the conversion. I only even noticed it was in Legacy mode because I was not able to boot into the BIOS and at first thought it was because fast boot was enabled, but turning that off still didn't allow be to get into the BIOS and wound up here. The motherboard is a Gigabyte B450M DS3H.

 

Any help is appreciated on next steps. Trying to avoid just formatting and starting over.

[C2dan88]

At the time of installing Windows did you only have the m.2 drive installed? if you had  more than one drive connected windows would of put the bootloader onto a different drive.

Check disk manager for which drive has the System Reserved partition.

[CTRL-ALT-DEFEAT]

Thanks for the reply. Disk Management shows that Disk 2 contains the boot partition and a second partition on the drive for recovery.

 

I did have the additional HDDs I'm using on this system installed prior to installing Windows to the SSD, but the boot loader seems to be on the correct drive... just is appearing as Disk 2 but read that shouldn't be relevant.

 

Thanks again.

 

 

[demonix00]

I'd have to hazard a guess that it's expecting an EFI system partition to be present on the drive (which is what would be expected for a UEFI system as there would be 3 partitions and not 2 for a boot drive) and it's failing because it can't find it, so you might be better off backing up any critical data from the drive, disconnecting any other drives that are connected to it and secure erasing the SSD ready for a fresh install of windows 10 (with the SSD being the only drive connected to prevent the bootloader from being put onto another drive).

[CTRL-ALT-DEFEAT]

Ack... Well I figured out the System partition is loaded onto Disk 0 with the Boot and Recovery on Disk 2. Since it was already failing validation for Disk 0 in the first place, I guess there is no avoiding re-installing the OS.

 

Thanks for the help!

 

 

[homeap5]

You can use EasyBCD, move/create boot files to the same partition as system (yes, it's possible in mbr legacy mode) and then use mbr2gpt without problem.

[CTRL-ALT-DEFEAT]

So just coming back to thank you all again. I followed what homeap5 recommended and used EasyBCD to move the System partition from Disk 0 (G: on my system) to Disk 2 (C: on my system) and then I was able to successfully get MBR2GPT to validate Disk 2 and then ran the conversion to UEFI successfully... hooray!... except after restarting... blue screen stating the disk needed to be recovered. Shut it down... plugged in a USB drive with Windows installation media on it and... still blue screen. Keyboard and mouse drivers were not loaded either so was totally stuck here . I knew I needed to get into the BIOS and disable CSM for UEFI boot....

 

Fortunately, my older M.2 still had Windows installed on it and I knew it was already set to UEFI, so I popped in and got into the BIOS and disabled Ultra Fast Boot and CSM.

 

Put the 970 EVO NVMe back in and voila... back in business and running in UEFI.

 

This whole thing started because I needed to get into the BIOS to enable the XMP profile.

 

TL;DR - Got it working thanks to the help here and didn't need to re-install Windows after all.

 

Thanks again!

[homeap5]

I'm happy that you used more advanced method than reinstalling. Nice to hear that someone can solve problem with only little help without step by step instructions (which is pointless, because people mostly avoid complex tutorials anyway and those who not - don't need them).