By Bryce / Last Updated May 4, 2023

When should you convert MBR disk to GPT in Windows 10?

Generally speaking, you intend to convert Windows 10 MBR disk into GPT under the four following situations:

1. Make full use of large disk space. MBR supports disk size up to 2TB, to use the capacity beyond 2TB, you can convert MBR into GPT.

2. Great more partitions. MBR disk only supports 4 primary partitions or three primary partitions plus one extended partition. As for the GPT disk, it almost has no limitation to the number of partitions.

3. Solve the error “ Windows cannot be installed to this disk. The selected disk has an MBR partition table. On EFI systems, windows can only be installed to GPT disk…" when installing Windows 10.

4. Upgrade to Windows 11: You can upgrade to Windows 11 from Windows 10 but your system disk should be a GPT disk as it requires UEFI boo mode. Thus,  you need to convert system MBR disk to GPT for Windows 11 upgrade.

Two Methods to convert Windows 10 MBR into GPT without data loss

In fact, we can make Windows 10 MBR to GPT conversion with Windows built-in tool Disk Management or Diskpart. However, both the two ways will require you to delete all partitions first, which means that you have to bear the loss of data or experience the cumbersome process of data backup and restoration.

Thus, here introduce another two ways about how to convert a disk from MBR into GPT without losing data in Windows 10. You can choose one way based on the specific situation.

#1. Convert Windows 10 system disk to GPT via MBR2GPT

According to Microsoft, MBR2GP.EXE, first known in Windows 10 version 1703, is a built-in utility located in Win\System 32 directory. In Windows 10, MBR2GPT can convert MBR system disk to GPT without data loss since it won't delete data during the conversion. You can apply MBR2GPT in the following steps:

Note: Confirm that your device supports EFI/UEFI Boot Mode before converting MBR to GPT.

Press “Windows” + “R”

MBR2GPT Convert

MBR2GPT utility is available only in Windows 10 version 1703 or later.
If the MBR disk is with BitLocker-encrypted volumes, it is recommended to suspend the protection at first. After conversion, you can delete the existing protectors and recreate them to resume BitLocker.
After converting the system disk from MBR to GPT, enter BIOS to change Legacy to EFI/UEFI.

#2. Convert Windows 10 MBR system / data disk into GPT via a GUI tool

Normally, Windows 10 MBR2GPT can convert MBR system disk to GPT successfully. However, sometimes, you can meet an error message, such as “disk layout validation failed for disk 0”. If you don’t want to spend time fixing MBR2GPT error, you can turn to this great conversion tool: AOMEI Partition Assistant Professional. Have a look at its highlights:

✌ It has a modern and user-friendly graphic interface, enabling you to complete MBR disk into GPT conversion in Windows 10 effortlessly within a few clicks.
✌ It can allow you to change disk partition style into GPT without losing data not only in Windows 10 but also in Windows 7/8/8.1/11.
✌ Apart from the system MBR disk, you can use it to convert MBR external hard drive to GPT without deleting any partitions.
✌  If you have converted a wrong disk into GPT accidentally, you can use this tool to convert the GPT disk back to MBR.

Now, install and run it on your Windows-based machine and refer to the following steps to start Windows 10 MBR to GPT conversion.

✍ You can download the demo version to have a try at first.

Download Demo Win 11/10/8.1/8/7/XP
Secure Download

Notice: If your computer is a laptop, make sure that the power supply is sufficient.

Step 1. Right-click the MBR disk that you need to convert to GPT and choose “Convert to GPT”.

Convert System Disk To Gpt

Step 2. Confirm the operation and click “OK”.  Then, make sure that your system supports EFI/UEFI mode and click “Yes”.

Ok To Gpt System Disk

Step 3. You will turn to the main menu. Check the pending operation and click “Apply” to execute your operation.

Apply To Gpt System Disk

 For converting the partition style of the system disk from MBR to GPT, a reboot is required.
 Before converting the MBR system disk into GPT, make sure that the machine supports UEFI boot. After converting, to boot successfully from the system disk, you need to enter BIOS to change Legacy to EFI/UEFI.
 To convert a disk into GPT in Windows Server 2022/2019/2016/2012(R2)/2008 (R2) without data loss, you can use AOMEI Partition Assistant Server.

How to convert MBR to GPT during Windows 10 installation without data loss?

When messages such as “Windows cannot be installed to this disk. The selected disk has an MBR partition table” appear, it is highly recommended to convert the disk from MBR to GPT to fit UEFI boot mode. As Windows 10 is unable to boot, you can create a bootable media via AOMEI Partition Assistant and then convert MBR to GPT during Windows 10 installation.

Step 1. Plug in USB or CD/DVD to a working computer running Windows 10, fire up AOMEI Partition Assistant Professional, and click "Tools" > “Make Bootable Media” on the main interface.

Make Bootable Media

Step 2. In this Window, select the way to make bootable media according to your device. Then, click “Proceed”.

Choose Usb Drive

Step 3. Click “Finish” when the operation progress is over.


Step 4. Plug in the bootable device to the computer that you plan to install Windows 10 and boot from the bootable media.

Boot from the Bootable Media

Then, the following steps are as same as the steps to convert Windows 10 MBR to GPT via AOMEI Partition Assistant software.

PS.: All the data on the device will be formatted; it is suggested to back up your important data on the device.