By Lucas / Last Updated March 4, 2022

Why Convert GUID Partition Table to MBR?

Although GUID Partition Table (GPT) is a new disk layout and has some advantages, there are still some situations that need converting GUID Partition Table (GPT) to Master Boot Record (MBR). Let’s look at the following two examples from the computer forum:

1. I have a Lenovo U510 and it came installed with Windows 8, but I want to install Windows 7 instead. The Windows 7 installation would not let me install it because the drive is formatted to GPT (Both 24GB SSD and 750GB hard drive). What should I do?

2. I wiped my Windows 8 thinking I could install Windows 7 x86 but I can’t because the disk is GPT. I need to convert to MBR. Is there a tool to do that?

3. When I boot my computer up, it’s unable to boot from the hard drive, as the BIOS just says can’t boot to the hard drive. But when I take the drive out and put it into another computer (XP, 32 bit) to try to recover files, it doesn’t show up in Windows explorer, but shows up as a GPT protective drive (healthy) in administrative tools > storage utility, with no drive letter but just a blank next to the hard drive icon

Convert GUID Partition Table(GPT) to Master Boot Record(MBR)

The second example asked a question “Is there a tool to do that?” The answer is yes. A professional partition software named AOMEI Partition Assistant Professional can do this without data loss, and you can convert the system disk between GPT and MBR without reinstalling OS. It supports Windows 11/10/8/8.1/7/XP/Vista system to help Windows users to manage their devices.

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Method 1. Convert GUID partition table to MBR via AOMEI Partition Assistant

Step 1. Install and run AOMEI Partition Assistant Professional Edition. Right-click Disk 1 and select “Convert to MBR Disk”.

Convert Data Disk to MBR

Step 2. Confirm that you want to proceed by clicking OK.

OK MBR Data Disk

Step 3. Preview the pending operation under ‘Pending Operations’, if you want to proceed click Apply.

Apply to MBR Data Disk

Only needs a few steps, Simple, right?

Method 2. Convert GPT to MBR with CMD

This method is converting GUID Partition Table(GPT) to Master Boot Record(MBR) via the command line.

Step 1. Right-click Command Prompt, and then click "Run as administrator".

Step 2. You need to type the following commands and hit enter after each one:
• Type list disk. Make note of the disk number you want to delete.
• Type select disk [number]
• Type clean.
• Type convert mbr

convert GPT to MBR

This method request the disk is empty and contains no volumes, so you should delete and clean first. I suggest you back up volumes by using backup freeware.

Method 3. Convert GPT to MBR with Disk Management

This method is converting GUID Partition Table (GPT) to Master Boot Record (MBR) with Windows disk management.

Step 1. Log on as an administrator.

Step 2. Right-click Computer and select Manage.

Step 3. Select Disk Management from the left pane under the Storage category.

Step 4. On the right pane, ensure that the hard disk drive on which you want to reinstall Windows has no partition. (If it has, deletes it first. Otherwise, the "Convert to MBR" option would be grayed out and would be disabled)

Disk management

Step 5. Then right-click the name of the disk (e.g. Disk 1) and click Convert to MBR from the context menu.

This method also requests the disk is empty and contains no partitions.

These methods are compared, you can see both methods 2 and 3 ask you to delete data on the disk. The biggest advantage of the first method is that don’t mind a disk is empty or not. AOMEI Partition Assistant is professional and safe. It has other amazing features such as migrating OS to SDD, cloning disk, converting file system between FAT32 and NTFS,  making Windows 11 to go USB... If you're a Windows Server user, please choose Server edition.