converts from the Master Boot Record (MBR) to the GUID Partition Table (GPT)

MBR2GPT.EXE converts a disk from the Master Boot Record (MBR) to the GUID Partition Table (GPT) partition style without modifying or deleting data on the disk.

MBR2GPT.EXE converts a disk from the Master Boot Record (MBR) to the GUID Partition Table (GPT) partition style without modifying or deleting data on the disk.

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