Convert MBR System Disk to GPT

[longinthetooth]

Is this still impossible?

''gptgen'' doesn't claim to be capable of doing it, but bloggers imply it can?

Like dmdordan I have been fooled.

Tom''s guides as fantastic as they are, doesn't seem to warn users about this issue or how to avoid it. I have installed a M.2 and SATA ssd disk. Although the m.2 is where I loaded win 10, the SATA has been set up (somehow) as the System disk. Both being MBR. Yet all the general info says MBR is old hat, only needed for portable storage, and SSD should only use GPT!

The process didn't give me any opportunity to Initialize either disk!

Was this setup at the factory level by the SSD manufacturer, the motherboard, the UEFI default, or Win 10?

Does having a legacy MBR HDD make a difference? My subsequent reading of the GPT definition implies it might?

I'd like to go back and start afresh, but it is looking very doubtful.

I understand that basic diskpart commands like clean and format required for catastrophic situations such virus and failures cannot be undertaken on system or bootable disks. Does that only apply to MBR or GPT as well?

 

[asoroka]

You need GPT for any disk larger than 2TB.

For disks smaller than that you can use MBR. There is no problem with using MBR for small disks.

If you must repartition the disk (you will lose all data) you can use the DiskPart command line program to create a GPT parttition.

 

[karenjoly]

You need GPT for any disk larger than 2TB.

For disks smaller than that you can use MBR. There is no problem with using MBR for small disks.

If you must repartition the disk (you will lose all data) you can use the DiskPart command line program to create a GPT parttition.

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. The tool is designed to be run from a Windows Preinstallation Environment (Windows PE) command prompt, but can also be run from the full Windows 10 operating system (OS) by using the /allowFullOS option.

MBR2GPT.EXE is located in the Windows\System32 directory on a computer running Windows 10 version 1703 (also known as the Creator's Update) or later. The tool is available in both the full OS environment and Windows PE.