How to Convert MBR to GPT via CMD Prompt Windows 11/10/8/7?

• Reasons to convert MBR to GPT
• Steps to convert MBR to GPT via CMD in Windows 10/8/7
• CMD alternative: convert MBR to GPT without data loss
• Convert MBR to GPT via CMD during OS installation
• Summary

Reasons to convert MBR to GPT

MBR and GPT are two different standards to define the layout of the partition table on the hard disk. And it is commonly acknowledged that GPT (GUID Partition Table) is better than MBR (Master Boot Record). Compared with MBR, GPT has several advantages, which might be the main reasons why some users want to convert MBR to GPT:

①GPT supports a disk larger than 2TB whereas MBR supports up to 2TB hard disk.

②GPT allows you to create 128 primary partitions while MBR allows you to create 4 primary partitions at most.

③Different from MBR, GPT stores the partitioning and boot information in multiple locations so that you can easily recover them when it is corrupted.

④Based on the official announcement that UEFI  is required when upgrading Windows 10 to Windows 11 via the "Check for Update" feature.

How to change from MBR to GPT via CMD in Windows

To change disk from MBR to GPT in Windows 11/10/8/7, the CMD command line is a great tool you can make use of. In CMD, you can choose Diskpart and MBR2GPT.

Notes:
①This method requires you to delete all partitions on the selected disk, so please back up all the data in advance.
② To use CMD to convert system disk from MBR to GPT, you have to enter the WinPE mode since the system-related partitions cannot be deleted within Windows.
③ MBR2GPT.EXE is available from Windows 10 version 1703. And it only works for the system disk.

Oprion 1. Use Diskpart to convert disk to GPT

Step 1. Open an elevated Command Prompt: Press Win+R on your keyboard to open Run dialogue, in which type cmd and hit on Enter.

Step 2. In the elevated Command Prompt window, type diskpart and press Enter to launch DiskPart Windows. And execute the following commands in sequence.

▶list disk (display all the online disks）

▶select disk n (n represents the number of the target MBR disk)

▶clean (remove all partitions on the target disk if there are)

▶convert gpt

This demonstration is based on converting a data disk. After the conversion is finished successfully, type "Exit" and press "Enter" to leave this window.

Option 2. Use MBR2GPT to change MBR to GPT

To convert MBR system disk to GPT disk with MBR2GPT tool , here you can follow the command lines in different situations.

If you are working under Windows PE, type: mbr2gpt /convert /disk:n

If you are working in the full OS environment, type: mbr2gpt /convert /disk:n /allowfullOS

CMD alternative: convert MBR to GPT without data loss in Windows 11/10/8/7

From the above, we know it is necessary to backup the MBR disk before you convert MBR to GPT via CMD to avoid losing important data. And MBR2GPT is not developed for all disks. So you might wonder whether it is possible to convert data and system MBR disk to GPT without deleting partitions and losing data. Luckily, it is fully possible with the help of AOMEI Partition Assistant Professional. This software can convert both data and boot disk from MBR to GPT without removing any existing partitions. (You can download the demo version to simulate the operation.)

Supported OS: Windows 11, Windows 10, Windows 8, Windows 7 (32-bit and 64-bit).

Step 1. Install and run AOMEI Partition Assistant. Right-click the disk you want to convert to GPT and select “Convert to GPT”.

Step 2. Confirm your operation by clicking “OK” to continue.

Step 3. Click “Apply” button on the toolbar to commit the pending operation.

Wait for a while, the conversion will be finished.

Convert MBR to GPT via CMD during OS installation

If you meet the error "Windows cannot be installed to this disk. The selected disk has an MBR partition table. On EFI system, Windows can only be installed to GPT disks" during the Windows installation process on your PC, you can convert MBR to GPT via CMD during installation to solve this problem. Below we will take how to change disk from MBR to GPT in Command Prompt when you install Windows 10.

Notes:
①Converting system disk to GPT using CMD will wipe all data on the system disk.
②Before converting boot disk from MBR to GPT, you need to ensure your motherboard supports UEFI boot mode since you have to change boot mode from Legacy BIOS to UEFI after conversion.

Step 1. Boot your computer from the Windows installation CD/DVD.

Step 2. Wait for the "Windows Setup" screen.

Step 3. Press “Shift + F10” keys together on the keyboard to open the command prompt window.

Step 4. Type “Diskpart” into the CMD window.

Finally, execute the commands “list disk->select disk #->clean ->convert gpt” to convert the disk from MBR to GPT.

If you are not able to boot from DVD media, that is, your PC does not have an optical drive, you can turn to AOMEI Partition Assistant Professional as well, with which you can create a bootable flash drive and convert MBR to GPT without booting into Windows or deleting existing volumes/data.

Note: An empty USB drive is required and you need to connect it to a working Windows computer.

Step 1. Install and launch AOMEI Partition Assistant Professional on the working PC. Click "Tools" > “Make Bootable Media” and follow the wizard to create a bootable USB drive.

Step 2. Plug the created bootable USB drive into the computer whose OS installation process is interrupted by the MBR to GPT conversion issue, change the boot priority to the USB drive and boot your computer from it.

Step 3. Once login, you will enter the main interface of AOMEI Partition Assistant Professional. Right-click the system disk and select “Convert To GPT”.

The rest steps are similar to the above part on converting data disk to GPT.

Wrapping things up

Above is all about how to convert MBR to GPT via CMD and using AOMEI Partition Assistant. Obviously, AOMEI Partition Assistant is a much wiser choice if you want to convert MBR disk to GPT without deleting existing partitions or losing data on the MBR disk.

If you are running Windows Server operating system, you can try AOMEI Partition Assistant Server, which owns all features of Professional edition such as migrate OS to SSD/HDD, copying MBR disk to GPT disk, or GPT disk to MBR, etc, convert dynamic disk to basic without removing volumes, and more compatible (both Server and Windows PC are supported).

FAQs about convert MBR to GPT via CMD

Why would I need to convert MBR to GPT?

Converting from MBR to GPT is necessary when you want to utilize features that are only available with GPT, such as support for drives larger than 2TB or more than four partitions on a disk.

Can I convert MBR to GPT without losing data?

Yes, it is possible to convert MBR to GPT without losing data, but it's essential to backup your data beforehand as the process involves modifying the disk's partition structure, which carries a risk of data loss if not done correctly.

What tools can I use to convert MBR to GPT?

There are several methods, but using the Command Prompt (CMD) utility built into Windows is a common and reliable approach for converting MBR to GPT, and of course, AOMEI Partition Assistant is always for you.

Is there a risk involved in converting MBR to GPT?

Yes, there's always a risk when modifying disk partitions. While the conversion process itself is usually safe, errors or interruptions during the process can lead to data loss or an unusable disk. Hence, it's crucial to follow instructions carefully and backup important data before proceeding.

Can I convert back from GPT to MBR if needed?

Yes, it is possible to convert back from GPT to MBR, but it typically involves wiping the disk entirely, thereby causing data loss. Therefore, it's recommended to consider the implications carefully before converting from MBR to GPT.