How to Convert MBR to GPT with Windows Installation Media

Learn how to convert MBR to GPT with Windows installation media CMD or a handy tool to avoid data loss.


By Lucas / Updated on May 12, 2023

Share this: instagram reddit

Windows installation media and MBR & GPT

People often use Windows installation media to install OS or repair some computer problems like BSOD or rebuilding MBR. And some users also use it to convert a system disk from MBR to GPT partition style.

MBR and GPT are two different partition tables for disk, all disks need to be initialized to either MBR table or GPT table before using. More users have a partiality for GPT disk because it can support larger size disk and more partitions in newer computers. While MBR is the older one that only supports 2TB capacity and 4 primary partitions in a hard drive.

How to convert MBR to GPT with Windows installation media?

GPT and MBR partition styles have various distinguishes, one among all is that some later operating systems only allow users to install Windows on a GPT disk, if users attempt to install it on an MBR disk, they’ll see a pop-up window showing: “The selected disk has an MBR disk partition table.”

Windows OS list

Here we list all Windows systems for your reference. All 64- bit systems need a GPT disk as their system disk and also need UEFI boot mode, therefore, if you need to switch system disk from MBR to GPT, you need to make sure the system supports GPT. The others situation is that some wish to convert to GPT during the system installation when they use a Windows installation media.

No matter what situation you’re in, you can convert MBR to GPT with Command Prompt. Just pay attention that CMD will ask you to type a clean command to clear all partitions and data on the disk, so, make sure you have a backup of this disk.

Here’re the details:

Step 1. Plug in a Windows installation media and set basic information of language and location. When you see a Windows Setup window, please press “Shift”+ “F10” to open CMD.

Step 2. Type the following lines and hit “Enter” after each.

• diskpart
• list disk
• select disk x
• clean
• convert to gpt


Then you can close the windows to continue your operation.

The Command Prompt requires users to type the right command lines and you cannot recall your operation, so, make sure you input the correct orders and select the right disk number.

Convert system disk to GPT without Windows installation media

It’s necessary to do a backup of your disk if you choose to use CMD to execute the conversion. However, if you select AOMEI Partition Assistant Professional to convert your disk, things will be easier. It is a powerful disk/partition management tool, and the “Convert to GPT Disk” function makes it a reliable MBR to GPT converter for all Windows systems (Please choose Server edition if you’re using Windows Server). This tool can convert data/system disk from MBR to GPT, or GPT to MBR without losing data, therefore, you don’t need to waste time on backup.

Download Pro Demo Win 11/10/8.1/8/7/XP
Secure Download

Step 1. Install and run Partition Assistant, right-click your MBR disk, and select the “Convert to GPT” feature or click the MBR disk and choose "Convert to GPT" from the right column.

Convert system disk to GPT

Step 2. Click “OK” after reading the message.


Step 3. Click “Apply” in the interface to execute the conversion. If you regret executing the operation, you can click “Undo” to give up.


Then you need to restart your PC and go to BIOS to change the boot mode from Legacy to UEFI mode.

Final lines

Now you know how to convert MBR to GPT with Windows installation media. And with the developments of new tech, more and more users might choose GPT disk. AOMEI Partition Assistant can make the conversion simpler for all users, you can even use it to convert to GPT disk without OS.

What’s more, this practical software has more amazing features, such as, migrate OS, cloning disk/partition, converting file system between FAT32 and NTFS, resizing/deleting/merging/formatting/ partition, or moving applications

Lucas · Staff Editor
I prefer peaceful and quiet life during vacation,but sometimes I watch football match if my favorite club performs brilliantly in that season. And I love reading, painting and calligraphy, thus I send my friends festival handwriting cards every year.