How to Use MBR2GPT for Windows 11 Upgrade

Learn details about using MBR2GPT for Windows 11 upgrade preparation and another handy tool to convert disk without deleting any drive.


By Lucas / Updated on May 12, 2023

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GPT & Windows 11 upgrade

Believe you’ve already known that Windows 11 is the latest OS of the Windows family that requires UEFI boot mode for users who wish to upgrade from the previous systems. GPT is a different partition style from the MBR. It allows users to make full use of a disk whose storage space is larger than 2TB and supports more primary partitions than MBR. What’s more, if you wish to upgrade to Windows 11, it must be a GPT disk set as the system disk to match with UEFI boot mode.

For converting MBR system disk to GPT disk, Windows has a built-in tool called “MBR2GPT”. It might be a little unfamiliar for some users, let’s see more about this tool in the next part.


1. What’s MBR2GPT?

MBR2GPT.EXE is a converter of disk partition table that can convert a disk's partition style from Master Boot Record (MBR) to GUID Partition Table (GPT) without altering or removing data on the disk. The utility is intended to be launched from a Windows Preinstallation Environment (Windows PE) command prompt, but it may also be run from the full Windows 10 operating system (OS) by specifying the /allowFullOS.

Users who are using Windows 10 version 1703 or later versions can run MBR2GPT under the Windows\System32 directory.

▶ 2. What can you do with the MBR2GPT tool?

Convert system disk from MBR to GPT without data loss.

Convert MBR disk with BitLocker encrypted volume.

Convert operating system disks which installed earlier versions of Windows 10 (versions 1507, 1511, and 1607).

Create an EFI system partition.

▶ 3. Some disk requirements

⑴ Only the system disk can be converted via MBR2GPT.EXE.

⑵ The target MBR only has 3 partitions.

⑶ For a disk with BitLocker-encrypted volume, after you suspended the protection, the conversion is available.

⑷ If the disk is installed in earlier versions of Windows 10, users need to run the utility when booting into Windows 10 version 1703 or later and execute offline work.

MBR2GPT is a tool for Windows 10 version 1703 and later versions, Windows 7/8/8.1 systems are not in the supporting list. If you wish to convert disk in these systems, you’ll need to upgrade to Windows 10 at first.

How to use MBR2GPT for Windows 11 upgrade

If your disk meets all conditions this useful tool required, then let’s see how to use it.

Tip: Make sure your device support UEFI mode before we start.

There are two situations when you use this tool, the commands are different:

▶ In Windows PE, you need to type: mbr2gpt /convert /disk:n (n is the number of the system disk).

▶ In the full OS, you need to type: mbr2gpt /convert /disk:n /allowfullOS


After the conversion, you can reboot your PC and change the boot mode from Legacy BIOS to UEFI.

However, MBR2GPT has some errors. Users might meet:

1. Disk layout validation failed for disk x

mbr2gpt Validation Failed

2. MBR2GPT.EXE has stopped working

mbr2gpt stop working

3. Cannot Find OS Partition

mbr2gpt cannot find os

4. MBR2GPT is not recognized

MBR2GPT is not recognized

How to deal with all these troubles when you’re trying to use the MBR2GPT tool?

Alternative to MBR2GPT tool Windows 11

Well, the solution is simple, find a reliable alternative to MBR2GPT. AOMEI Partition Assistant Professional is such a reliable alternative. It is third-party disk management software that has a “Convert to GPT disk” feature. Why is this tool you need to replace MBR2GPT?

All Windows systems supported: 32-bit and 64-bit Windows 11/10/8/8.1/7/XP/Vista. Windows Server users can choose Server edition.
Convert system disk and data disk from MBR to GPT without losing data.
Only 3 steps you can finish the conversion.
Free Download Win 11/10/8.1/8/7/XP
Secure Download

Before the conversion:

1. Don’t forget to change the boot mode from Legacy BIOS to UEFI after the conversion.

Step 1. Install and run AOMEI Partition Assistant. Click the system disk and choose “Convert to GPT” from the right toolbar.

convert system disk to gpt

Step 2. In the next window, click “OK” to confirm your operation.


Step 3. Back to the main interface, click on “Apply” to commit the operation.


Then you can reboot the computer to change the boot mode.

Choose boot mode

See? It’s a pretty easy operation for all users.

And if you need, you can use this tool to execute the conversion even without the loading OS.

Final lines

MBR2GPT is a good tool once your disk meets all requirements, and you can also find MBR2GPT in Windows 11 to use to convert system disk. But, if you wish to convert both system and non-system disks without the limitation of Windows edition, the number of partitions, and most important without modifying any data, we suggest you select AOMEI Partition Assistant.

Besides, it has other convenient features such as migrating OS without reinstalling, cloning disk/partitions, creating Windows to Go USB, SSD secure erase, App mover…etc. to help you organize your disks.

Lucas · Staff Editor
I prefer peaceful and quiet life during vacation,but sometimes I watch football match if my favorite club performs brilliantly in that season. And I love reading, painting and calligraphy, thus I send my friends festival handwriting cards every year.