Utilizing an Interface of the Windows

By pressing right tab of mouse on My Computer, click on Manage. After that click Disk Management. Then again pressing right tab of mouse on GPT disk which you feel to modify into MBR disk, then press Convert to MBR disk.

Utilizing a Command Line

1. At a command prompt, type: diskpart, and then press ENTER.

2. At the diskpart prompt, type: list disk, and then press ENTER.

3. Record the disk number of the disk that you want to convert to an MBR disk.

4. At the diskpart prompt, type: select disk n, and then press ENTER.

5. At the diskpart prompt, type: convert mbr, and then press ENTER.
If your computer is associated to a network, the network policy configuration may prevent you from completing this procedure for that you must be signed in as member of the Administrators or an administrator a set to fulfill this procedure.

On Itanium-based computers, you can change a disk from GPT to MBR, provided that the disk is empty.