Windows 10: Converting Windows 10 MBR Disk to GPT

I have two internal disks and one external on my desktop. One of the internals is a GPT 1Tb disk for data and archive storage. The other is an MBR Windows 10 system disk and the external one is a 1TB USB. The system disk contains a System Reserved partition and the Windows 10 partition.

Would there be any advantage to converting the MBR disk to a GPT if it could be done?

Thank you.

:)

 

3TB Drive format windows 10 not working

This is because your hard disk is MBR disk, you can check it in Disk Management.
which only supports 2 TB drive. so the only way to get your space backup is to convert your disk back to GPT disk. Disk management can only convert a disk to MBR when it is empty. Therefore, you need a third party software to

convert MBR to GPT on Windows 10 without affecting the OS, such as AOMEI Partition Assistant.after installing this software, the Convert mBR/GPT wizard will guide you through the process. How to Convert GPT to MBR or Convert MBR to GPT without Losing Data?

 

Windows Installation

On EFI systems, Windows can only be installed to GPT disks. If you use MBR disk, you will receive this error message: Windows cannot be installed to this disk. The selected disk has an MBR partition table. You can convert MBR to GPT and try it again.

 

The main reason to convert an MBR disk to GPT is either because you have a UEFI Bios boot computer or the HDD is larger then 2.2TB. Any Drive larger then 2TB must be Initialized GPT to recognize the whole drive in one partition. Or you can create two MBR partitions. If a GPT drive is the boot drive, it will only work in a UEFI Bios, you cannot boot a Windows OS on a GPT drive unless it is UEFI Bios.
To convert an MBR disk to GPT you must re-Initialize it. This will wipe all data off of the drive.
Since your OS drive is 1TB and your Bios is probably not UEFI, there is no advantage to converting to GPT and in fact you would have to reinstall your Windows OS, which also won't work unless your Bios is UEFI.

 

How big is that system disk? Most times it will be either a smaller partition like mine at 150GB [C:] on a 1TB HDD with the rest being the Data [D:] partition. Or it may be a separate smaller SSD of maybe 128GB or 256GB with a second physical drive of 1TB.

 

If you have a UEFI bios and you want to convert the boot drive to UEFI, you can make an image backup of your OS partition to another drive. Wipe the hard drive, convert it to GPT, do a clean install of Windows 10 to it as a GPT format drive. Then replace the newly created OS partition with your previously saved OS partition.

Even if your computer is UEFI - the only real advantage to GPT on a 1 TB hard drive is the ability to create more than 4 partitions if you want to without having to have an extended partition and logical drives.

 

The Macrium procedure to convert an MBR to a GPT disk:
Restoring an MBR System image to UEFI/GPT - KnowledgeBase - Macrium Reflect Knowledgebase
This is a destructive process (original info is lost).

Another procedure:
https://social.technet.microsoft.com...n-to-uefi.aspx.
This procedure is non-destructive.

Neither of these processes create the GPT Recovery (WinRE) partition, and in both cases the WinRE may not work after the conversion.

 

Thank you very much everyone. Clearly, I will just leave everything as it is.

 

The Macrium Reflect procedure worked for me on 2 different machines. Some partitioning tools now support the conversion natively. Not sure if any of their free ones do, yet.
Convert System Disk from MBR to GPT within 3 Steps – EaseUS

 

The procedures supported by partition tools usually apply only to data (non boot) disks.

MiniTool Partition Wizard claims to support the procedure for boot disks in the paid version of v. 10.x, but I checked and the procedure failed, reports that the MBR disk doesn´t contain the necessary EFI files (obvioulsy it doesn´t, it´s an MBR disk).