What is MBR Disk(Master Boot Record)?

Here, you are going to learn what is MBR disk, its advantages and disadvantages. In addition, a step-by-step guide of convert MBR to GPT or GPT to MBR will be provided.


By AOMEI / Updated on September 12, 2023

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What is MBR disk?

An MBR (Master Boot Record) disk is a type of storage device organization method used in older computer systems. It serves as the structure that defines how data is organized on the disk. MBR disks were the standard for a long time, but they have limitations, especially in terms of partitioning and capacity, compared to the newer GPT (GUID Partition Table) disks.

Advantages of MBR disk

However, many people still insist on using the MBR partition table because it offers these advantages:

Legacy Compatibility: MBR is compatible with a wide range of older hardware and operating systems. This makes it suitable for systems that do not support the newer GPT scheme.

Widespread Support: MBR is a well-established standard and is widely supported across various operating systems and software applications.

Bootable on Older Systems: MBR disks can be used to boot older computers that have BIOS (Basic Input/Output System) firmware, which was common in computers built before the widespread adoption of UEFI (Unified Extensible Firmware Interface).

Drawback of MBR disk

An MBR disk takes Master Boot Record as the partition table. It consists of a sequence of 512 bytes located at the first sector of a data storage device such as a hard disk. Due to the fact that the MBR is a quit old partition structure for Windows systems, it is kind of out-of-date and has some disadvantages, compared with the newer partition table GPT (GUID Partition Table):

Limited Partition Count: MBR disks have a limitation of four primary partitions, or three primary partitions and one extended partition. This can be a significant limitation for systems with complex storage needs.

Partition Size Limit: MBR disks have a maximum partition size of 2 TB. Some users reported that their 4TB hard drive only shows 2TB, it is probably because they use MBR partition table on a large hard drive. This can be a major drawback when dealing with modern, large-capacity hard drives. 

Risk of Data Loss: MBR disks can be more susceptible to partition table corruption, which can lead to data loss if not backed up properly. This is due to the reliance on a single partition table.

Incompatibility with GPT: MBR and GPT are not compatible with each other on the same disk. This can be an issue if you want to use a drive with both older and newer systems.

Lack of Redundancy: Unlike GPT disks, MBR disks do not have a backup partition table. In case of partition table corruption, recovery can be more challenging.

Comparison Mbr And Gpt

How to convert MBR to GPT without losing data

MBR disks have served as a reliable standard for many years, but they have limitations in terms of partition count and size compared to GPT disks. While MBR is still used in some situations, especially with older hardware or smaller drives, GPT has become the preferred choice for modern systems due to its ability to handle larger capacities and provide enhanced features.

If you need to change a disk from MBR to GPT partition style, you can turn to the AOMEI Partition Assistant Professional. This is a comprehensive disk partition management expert that can convert GPT to MBR or MBR to GPT without deleting data, even the system disk. And it works well on Windows 11/10/8/7/Vista/XP.

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 Step 1. Install and launch AOMEI Partition Assistant Professional, right-click on the target disk and select “Convert to GPT”.

convert t gpt

Step 2. When prompted with the message saying “Are you sure to convert the selected disk from MBR to GPT disk”, hit “OK” to proceed.


Step 3. Hit “Apply” as the screenshot shows to commit the pending conversion operation.



Now, you should know what is MBR disk and its advantages and disadvantages. MBR is the traditional partition table format, rely on its great compatibility, there are still lots of people who are using MBR disk. If you want to change the partition style, you can convert MBR disk to GPT with AOMEI Partition Assistant, which is easy to use.

AOMEI · Staff Editor