Had to convert the GPT disk to MBR when I was unable to install Windows OS on the Disk Partitions available. Master Boot Record (MBR) disks use the standard BIOS partition table. GUID Partition Table (GPT) disks use Unified Extensible Firmware Interface (UEFI). One advantage of GPT disks is that you can have more than four partitions on each disk. GPT is also required for disks larger than two terabytes (TB). Please see how to create volumes via the Command Prompt in Windows. See how to upgrade Windows 10 with an unsupported CPU and TPM 1.0 to Windows 11.

You can change a disk from MBR to GPT partition style as long as the disk contains no partitions or volumes.

Steps to convert a GPT disk into an MBR disk error

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, and how to extend System Drive Partition on Windows.

Using the command line

1. Open an elevated command prompt by right-clicking Command Prompt and then choosing Run as Administrator.
2. Type diskpart. If the disk does not contain any partitions or volumes, skip to step 6.
3. At the DISKPART prompt, type list disk. 

Note the disk number you want to convert.

4. At the DISKPART prompt, type select disk <disknumber>.
5. At the DISKPART prompt, type clean.
6. At the DISKPART prompt, type convert mbr

Note: Running the clean command will delete all partitions or volumes on the disk. Please see System Drive Conversion: MBR to GPT on Windows 10, and Run MBR and GPT conversion with the best GPT converter.

Before you convert a disk, backup any data on it and close any programs that are accessing the disk. (But if you are installing an OS from scratch like me, there is no need to perform this).

I hope you found this blog post on how to convert a GPT disk into an MBR disk error helpful. Please let me know in the comment session if you have any questions.