By Cherry / Last Updated February 28, 2021

Review of MBR2GPT tool

MBR2GPT is a disk conversion tool built-in Windows 10 v1703 and later versions. It supports Windows 10 users to convert an MBR disk to a GPT disk without modifying or deleting data on the disk. MBR2GPT.EXE is located in the Windows\System32 directory on a computer running Windows 10 version 1703 or later. It is designed to be run from a Windows Preinstallation Environment (Windows PE) command prompt, but can also be run from Windows 10 operation system by using the /allowFullOS option.

With the MBR2GPT tool, you can convert any attached MBR-formatted system disk to the GPT partition format. You can also convert operating system disks that have earlier versions of Windows 10 installed, such as 1507, 1511 and 1607 by running MBR2GPT while booted into Windows 10 version 1703 or later, and perform an offline conversion.

How to use MBR2GPT conversion tool?

Compared with MBR disk, GPT disk has many advantages:

MBR disk only supports up to 4 primary partitions while GPT disk breaks out the limitation and allows you to create up to 128 primary partitions.

MBR disk supports up to 2 TB capacity. If your disk capacity is out of 2 TB, you cannot full use it when it comes with MBR disk type. While GPT disk supports disk capacity more than 2TB, which is more suitable for disk which have large capacity.

And because of the advantages of GPT disk, users would like to convert the MBR disk to GPT disk for a better use. Before converting, you need to know:

  • As for MBR2GPT tool is built-in Windows 10 v1703 and later versions, you need to make sure your operating system supports it.

  • To use MBR2GPT conversion tool, you need to be familiar with those two commands to satisfy with the different situations:

mbr2gpt /convert /disk:n (n refers the disk number you want to convert to GPT disk. This command is suitable if you are working under Windows PE).

mbr2gpt /convert /disk:n /allowfullOS (n refers the disk number you want to convert to GPT disk. This command is suitable if you are working in the full OS environment ).

Then, you can use the MBR2GPT disk conversion tool to convert MBR disk to GPT disk with the commands we mentioned above. For example:


However, the MBR2GPT disk conversion toll always comes into trouble. You may meet the MBR2GPT errors like MBR2GPT missing, MBR2GPT failed, or you may receive the error “disk layout validation failed for disk 0”. Besides, MBR2GPT disk conversion tool does not support to convert GPT disk to MBR disk. Well, for those situations, it is necessary to find the best alternative to MBR2GPT disk conversion tool.

The best alternative to MBR2GPT disk conversion tool

AOMEI Partition Assistant Standard should be the best free alternative to MBR2GPT disk conversion tool. It allows you to convert disk between MBR to GPT, and you won’t lose any data during the operation. That means you can use it to safely convert MBR to GPT, or convert GPT to MBR. If you need to convert system disk between MBR and GPT without reinstalling OS, you can upgrade to AOMEI Partition Assistant Professional to unlock this feature and more advanced features.

Download AOMEI Partition Assistant Professional for free trail.

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Install it to your Windows PC and start to convert system disk from MBR to GPT with the function Convert to GPT Disk.

Convert MBR System Disk to GPT


  • You need to ensure that your computer supports UEFI before converting the OS disk to GPT; otherwise, the disk would not boot after converting.

  • After the MBR OS disk has been converted to GPT partition style, you need to reconfigure the firmware to boot in UEFI mode.

  • Windows 32 bit doesn’t work on a GPT disk. If you need to convert the 32 bit OS from MBR to GPT, you need to upgrade the system to 64 bit before converting.

  • If you are Windows Server users, AOMEI Partition Assistant Server supports Windows Server 2003, 2008, 2012, 2016, 2019 and all Windows PC OSes.

  • AOMEI Partition Assistant should be the best alternative to MBR2GPT disk conversion tool. The one of the reasons is it can keep data safe during the operations. But you’d better to backup data in advanced in case of some unexpected situations which may cause data loss. Try AOMEI Backupper 90-day trail to keep your data safe.