
Upgrading your System Drive from MBR to GPT is crucial for Windows 10 to Windows 11 transition on older hardware with UEFI support. This change ensures proper booting, especially when “Secure Boot State” is Off and “BIOS Mode” is set to Legacy.
In that case, you should make a backup of your System Drive, follow the instructions below to convert the installation from MBR to GPT and proceed with the procedures to enable Secure Boot. To convert the partition type from MBR to GPT without reinstalling Windows 10, use the MBR2GPT command-line program. Here are some exciting guides: A brief Introduction to Linux and how to create disk partition in Ubuntu Linux, and How to encrypt a partition with Cryptsetup.
Here are other related guides: How to convert a GPT disk into an MBR disk – Error: Windows cannot be installed on drive 0 Partition 1, How to extend System Drive Partition on Windows, to create a disk volume see: How to create volumes via the Command Prompt in Windows, and How to upgrade Windows 10 with an unsupported CPU and TPM 1.0 to Windows 11.
How to check the Partition Style on a System Drive
Follow these steps to determine the current disk partition style. To open Disk Management, press the Windows key + R to bring up Windows Run, then type diskmgmt.msc
and click Ok for the System Drive.

Right-click the drive on which Windows 10 is installed and choose Properties of System Drive.

Click on the Hardware tab of the System Drive, and in the lower-right corner of the page, click on Properties.

In the Properties page, click on the Volumes tab. To view the Disk Information, click on Populate. In the “Partition style” section, if it says GUID Partition Table (GPT), the disk does not need to be converted; however, if it says Master Boot Record (MBR), you can use the System Drive conversion tool to convert.

Press the Cancel button and exit the Disk management.
Once you’ve completed the procedures, follow the instructions below if the System Drive requires conversion.
How to Convert MBR to GPT Partition Style
To convert an MBR partition to a GPT partition in Windows 10 System Drive, follow these steps:
Press the Windows Key to access the Start menu and look for the Settings option.

Click on Update & Security.

Click on the Recovery tab. Under the “Advanced Startup,” click on Restart now.

After the system restarts, click on Troubleshoot.

Click on Advanced options.

Click the Command Prompt option.

Select your administrator account and sign in if required. Enter the following System Drive command to confirm that the drive meets the requirements: mbr2gpt /validate
Use the mbr2gpt /? command to examine all of the possible choices.

Enter the following command to convert the disk from MBR to GPT: mbr2gpt /convert

Close the Command prompt and click the Turn off your computer option.
After completing the System Drive conversion, the command-line program will alter the partition type to GPT to meet the system requirements for installing Windows 11.
I hope you found this blog post on System Drive conversion helpful. Please let me know in the comment session if you have any questions.