Many users complain that they need to rebuild and repartition Windows 10 boot system file , then convert BIOS mode from legacy to UEFI without data loss. However, the System Reserved partition were created in Disk 1 instead of Disk 0 as below:

Bellow error appears while running the converting command:
mbr2gbt /convert /allowFullOS / disk:0
Error: Disk layout validation failed for disk 0

Partition layout: The default partition layout for UEFI-based PCs is: a system partition, an MSR, a Windows partition, and a recovery tools partition. This layout lets you use Windows BitLocker Drive Encryption through both Windows and through the Windows Recovery Environment. But currently the partition layout is incorrect.

Resolution:
- Boot the computer using the Windows 10 installation media
- On the first screen, press SHIFT+F10 to bring up the command prompt. Run the following commands at the command prompt:
Diskpart
List disk
Select disk 0
List partition //find system reserved
Select partition 1
Format
active
Assign letter =g: //assign letter to newly formated partition
Select partition 2
Assign letter=c: //assign letter to windows installed partition
Exit diskpart
Bootsect /nt60 all /force //fixing the boot sector
Bcdboot c:\windows /s F: /f ALL
Bootrec /scanos
Bootrec /fixmbr
Bootrec /fixboot
Bootrec /rebuildbcd
Reboot the system an convert it to UEFI by MBR2GPT tool.