By Cherry / Last Updated December 6, 2019

The differences between MBR and GPT disks

There are two different way of storing the partitioning information on a hard drive, called MBR (Master Boot Record) and GPT (GUID Partition Table). So what’s the difference between MBR and GPT disks and why do you need to convert MBR to GPT?

MBR, the master boot record disk, uses the standard BIOS partition table, and supports up to 2 TB per single partition in Windows operating systems. It only supports up to 4 primary partitions, so If you want to create more partitions on an MBR disk, you have to change one of the primary partitions into an extended partition. With an extended partition you can create up to 128 logical drives, therefore, extending your limit beyond 4 partitions.

GPT, the GUID partition table disk, uses EFI instead of BIOS, and its volume limit is bigger than MBR disks so you can use it on drives with more than 2TB disk space and create a theoretically unlimited number of partitions. Unfortunately, it can only support Windows 64bit systems from Windows Vista onwards. You can still use GPT disks in 32 bit versions of Windows XP, 2003, 2000, etc.

Removable flash drives are the exception as they are recognized as MBR by default and can’t be converted to GPT.

Generally speaking, GPT disks have better performance than MBR, so, many users currently want to convert their master boot record (MBR) disk into GUID partition table (GPT) disk. If you want to know more about difference between MBR and GPT please read the linked article.

How to convert disk from MBR to GPT with DiskPart?

Windows Disk Management is a built-in tool that provides users with a way to convert disks to GPT within the Windows operating system. If you would prefer to use command prompt to convert the disks, then the DiskPart utility will be able to assist you. It should be noted that both the Disk Management tool and the DiskPart utility can only convert an empty MBR disk to GPT (and vice versa). To convert a disk from MBR to GPT using command prompt (cmd), you can follow the steps below:

Before you do, here are some helpful tips:

  • Backup the MBR disk that you want to convert in order to keep the data safe.

  • You can only convert basic MBR disks without any partitions or volumes into a GPT disk. If there are partitions or volumes, then you need to backup the data, and then delete all partitions or volumes before converting between MBR and GPT.

  • If you want to convert from MBR to GPT disk during the Windows installation, you should open command prompt by pressing Shift + F10.

Step 1. Click Start, type "cmd", and right click it, select "Run as Administrator", or press "WIN+R", type "cmd" and press Enter to open command prompt. Then, enter "diskpart" to run the utility.

Step 2. Type "list volume" to find out if there are any partitions or volumes on the MBR disk you want to convert to GPT. If there are, you need to use diskpart delete partition first.

Then, type "list disk", and press Enter, it will show you all the disks on your computer. Make note of the disk number that you want to convert to a GPT disk. Here we will take disk 1 as our example.

Step 3. Type "select disk 1", press "Enter", it will remind you that the disk 1 is selected.

Step 4. Type “clean” and press “Enter” to remove all the partitions and volumes on the selected disk.

Step 5. Type "convert gpt", press "Enter" to begin the operation. After a few moments, you will find that Command Prompt says DiskPart successfully converted the selected disk to the GPT format. Please have a look at the below screenshot.

Diskpart Convert GPT

If you want to convert a GPT disk to MBR, you can also use the following diskpart convert mbr commands.

How to Convert MBR disk to GPT without losing data

Although DiskPart can convert a basic MBR disk that doesn’t contain any partitions or volumes into a GPT disk, you must run DiskPart with administrator permissions. The majority of users are uncomfortable using command line. They feel that using the DiskPart utility is unnecessarily complicated especially as the DiskPart commands can’t be revoked once executed. If you don’t feel confident using DiskPart commands, then you can convert an MBR disk to a GPT disk with a professional partition manager. AOMEI Partition Assistant Standard, is a free program that helps you manage your system partitions, it lets you convert disks in an easy-to-use interface, and it supports nearly all Windows operating systems including Windows 10, 8, and 7. Importantly, AOMEI Partition Assistant is able to convert between MBR and GPT disks without losing data or requiring users to backup their disks.

Below we will show you how to convert an MBR disk to a GPT disk using AOMEI Partition Assistant!

1. First, download AOMEI Partition Assistant Standard [Freeware]. Install and launch it. In the main window, click the disk you want to convert and choose ‘Convert to GPT’ on the left control panel.

Convert Disk to GPT

2. Click OK on the popup window to confirm the operation.

GPT OK

3. Now you need to confirm the operation again, if there are no problems, click "Apply" in the top left-hand corner.

GPT Apply

Now we know how to use DiskPart to convert GPT with command prompt commands and AOMEI Partition Assistant to convert to GPT with its easy to use interface. Once the conversion process has finished you can use DiskPart create partition on the newly converted disk.

Tips: As a free partition manager, AOMEI Partition Assistant Standard Edition only supports converting a data disk between MBR and GPT. If you want to convert a system/boot disk between MBR and GPT, please upgrade from AOMEI Partition Assistant Standard Edition to AOMEI Partition Assistant Pro Edition.