Convert Disk between MBR and GPT in Windows 10 without Data Loss

November 22, 2018

This guide provides 3 methods to convert your disk between MBR and GPT in Windows 10/8/7, including Disk Management tool, DiskPart command utility, and AOMEI Partition Assistant.

Overview of MBR and GPT

MBR and GPT are two different disk partition styles. Below is a brief introduction to them.

  • MBR is short for Master Boot Record, whose maximum size of disk is 2TB. And it only allows you to create 4 primary partitions or 3 primary partitions plus 1 extended partition. If you want to create many partitions on MBR disk, the number of primary partition should be no more than three and plus one extended partitions, then you can make logical partitions on extended partition.

  • GPT, short for GUID Partition Table, does not have the limitation on the number of partition and the size of disk. But as for GPT, you should know that system installed on GPT disk can only be booted from UEFI (United Extensive Firmware Interface). Besides, removable media cannot be converted to GPT.

If you want to check if your Windows 10 disk is MBR or GPT, please refer to difference between MBR and GPT.

Why Convert Disk between MBR and GPT in Windows 10?

It is clear from what I mentioned above that MBR and GPT has their own advantages and limitations. So sometimes you might need to convert MBR GPT Windows 10.

  • If you have a MBR disk whose size is 3TB, the rest of 1TB will be showed as unallocated space in your Windows 10, but you can't use it since MBR can only support up to 2TB disk. Then, you will have to convert MBR to GPT to make full use of the storage space. 

  • On the other hand, some operating systems such as Windows XP 32-bit, Windows 2003 32-bit, Windows 2000, Windows NT4 don't support GPT disk. In these operating systems, GPT disk will be shown as GPT protective, and you are not allowed to access data in the disk unless you convert GPT to MBR.

How to Convert Disk to MBR or GPT in Windows 10?

To convert MBR GPT Windows 10, you can try the following methods.

Method 1. Use a third party software (without data loss)

To convert MBR to GPT or convert GPT to MBR in Windows 10/8/7 without losing data, it is recommended to turn to this powerful tool – AOMEI Partition Assistant Professional. Apart from supporting convert data/system disk between MBR&GPT without data loss, it even enables you to resize partition, merge partitions, make bootable CD, allocated free space, migrate OS to SSD, and more.

Before you do:

  • If you want to convert system disk between MBR and GPT styles, please change boot mode between UEFI and Legacy BIOS. After conversion, GPT system disk can start Windows 10 from UEFI boot mode.

  • If there are more than 4 partitions on GPT disk, you cannot convert GPT to MBR disk unless you delete some unused partitions and limit the primary partition number within four due to the limitation of MBR disk.

Follow the steps below to convert GPT to MBR.

Step 1. Download this software, install and launch it. Right click the Windows 10 GPT disk you want to convert (here is Disk 2) and then choose Convert to MBR Disk.

Convert to MBR

Step 2. Click "OK".

Click OK

Step 3. Click "Apply" to perform all the operations.

Click Apply

If you need to convert MBR disk to GPT, you just right click the MBR disk and choose “Convert to GPT Disk”. And then do as the prompt like the steps of converting GPT to MBR.

Convert to GPT

Notes: 

  • To guarantee PC can be booted successfully after the system/boot disk has been converted from MBR to GPT, you will need to enter into UEFI firmware settings, and switch from Legacy BIOS to UEFI mode. You may need to check your PC's or motherboard's manual for its specific instructions on how to change this setting.

  • To convert GPT disk to MBR or convert MBR disk to GPT during Windows 10 installation, you need to create a Windows PE bootable media on another computer, and then start up your computer from the bootable media to make the conversion.

Method 2. Use Disk Management (data loss)

Disk Management Windows 10 is a built-in tool which allows you to create, delete, format, extend, and shrink partitions, convert to GPT or MBR, etc. To use this tool, you should open it by right clicking This PC<Manage<Disk Management. And then right click the disk you want to convert (here take Disk 0 for example). In the pop-up menu, you can find convert to GPT disk unavailable. That’s because this tool only allows you to convert an empty disk between MBR and GPT successfully. That is to say, you need to first delete all partitions on the target disk if you want to fulfill conversion task, So it will cause data loss. 

Convert to GPT Grayed Out

Method 3: Use DiskPart Command Line (data loss)

Windows 10 DiskPart is also a built-in tool command-line utility, it also can help you manage partitions and do conversion between MBR and GPT. Like Disk Management tool, DiskPart only enables you to convert GPT to MBR or convert MBR to GPT when there are no partitions on the disk. If you satisfy the precondition, you can do as follows:

Step 1. Click "Start Menu" > input "diskpart" in the search box and press "Enter" > Click "Yes" to open command prompt.

Step 2. Input "list disk" and press "Enter".

Step 3. Input "select disk n" and press "Enter". n is the number of the disk you want to convert. (take "Disk 1" for example)

Step 4. Input "clean" and press "Enter" to delete all partitions or volumes on the selected disk.

Step 5. Input "convert mbr" and press "Enter" to complete the conversion from GPT to MBR format.

Convert to MBR with Diskpart

Summary

This article shows you how to convert MBR GPT Windows 10 in three different methods. If you care data on the disk you want to convert, AOMEI Partition Assistant is the best choice. Or you can first backup data, delete all partitions on the disk, then apply another two methods to finish the conversion, finally restore data. Obviously, AOMEI Partition Assistant provides the easiest way.