By Bryce / Last Updated August 19, 2019


“In order to make full use of my 3TB hard disk, I want to convert it from MBR to GPT. When I opened the disk Management and right click the disk, I only found that the option of “Convert to GPT” grayed out”. My friend told me that I had to delete all partitions on this hard disk if I wanted to convert it to GPT style and I could backup important data if I was unwilling to lose them. However, if I delete partitions, what I need to do is not only to backup and restore data, but also to partition hard disk again. I am wondering that whether there is a way to convert my disk form MBR to GPT without deleting my partitions?”

Convert MBR to GPT without data loss using MBR2GPT in Windows 10

As long as you apply appropriate tool, you’re capable of converting MRB to GPT without deleting your partitions. If the operating system of your computer is Windows 10 version 1703 or later, MBR2GPT, a built-in tool for converting MBR to GPT without data loss is suitable for you. What you need to notice is that this utility is only for system drive. That is to say, if there is no OS installed on the disk, it can’t be converted from MBR to GPT via MBR2GPT utility. You can do as follows to convert MBR system disk into GPT in Windows 10:

Run “Command Prompt” as administrator by pressing “Windows+ R” and type “cmd”>Type “mbr2gpt / convert / disk n / allowfullos” in the command prompt window.

* “n” is the number of the hard drive that you need to convert to GPT.


  • If there is BitLocker-encrypted volume on the disk, suspend it before converting disk. To resume BitLocker after conversion, delete existing protectors and recreate them.

  • Confirm that your device supports UEFI/EFI boot before converting and reconfigure the firmware after the operation.

Convert MBR to GPT without data loss using Gptgen in Windows

Gptgen is a command line utility allows you to convert hard disk from MBR scheme to GPT non-destructively. To apply Gptgen properly in Windows, here you can follow the steps below:

1. Download Gptgen from its official website and unpack it.

2. Press “Win+ R” and type “cmd” to run Command Prompt as administrator.

3. Type “gptgen.exe-w \\.\\ physicaldrive n”, where “n” is the number of selected drive.

Type “y” to continue the operationwhen you receive the message that “This tool cannot guarantee that such partitions will remain bootable after conversion” and “Do you want to continue? [Y/N]”.


  • Apart from Windows, Gptgen is suitable for Linux.

  • The conversion of dynamic disk from MBR style to GPT is not supported by Gptgen.

  • It is advised to backup important information and OS to avoid of data loss caused by wrong operations

An Easier way to Convert MBR to GPT without data loss in Windows

Although MBR2GPT and Gptgen are capable of converting MBR to GPT without deleting your partition, it seems that they are a bit complicated for common users to handle. And it is possible that different MBR2GPT errors will occur, which is rather bothering and disappointing for green hand. Thus, it is a good choice to turn to a simpler converter – AOMEI Partition Assistant Professional. With concise GUI design,this software is fairly simple to handle; with powerful technology, it permits you to convert boot or data drive from MBR to GPT. What’s more, the conversion from MBR to GPT via AOMEI Partition Assistant is available in dynamic disk as well. It is suitable for Windows systems, including Windows 10/8.1/8/7, XP and Vista. And if you want to use it on Windows Server, you can upgrade it to Server version.

The step-by-step instruction to convert disk is as follows:

Step 1: Install AOMEI Partition Assistant and launch it.

Step 2: Right click the disk that needs to be converted and select “Convert to GPT Disk”. Click “OK”.

Convert MBR to GPT without Deleting Your Partitions

Step 3: Click “Apply” to complete the operation in the main interface.

Apply Conversion

You can check the information of operation again and click “Proceed”.

Confirm Information


  • After converting, you can create new partition on the unallocated space or allocate the unalloacted space to the partition that need to be extended.

  • It is available to create a bootable media via AOMEI Partition Assistant to make disk conversion between MBR and GPT.


Obviously, converting MBR to GPT without deleting your partitions is easy to be performed via the three utilities mentioned above. You can choose any of them to convert MBR into GPT without data loss according to your own situations. When your disk and system meet the requirements of MBR2GPT, it is acceptable to choose MBR2GPT. When you are familiar with computer knowledge, you can convert MBR to GPT without data loss using Gptgen.When you are unfamiliar with command lines and want to seek out an easy way, it is a nice choice to apply AOMEI Partition Assistant.