Convert a GPT disk into an MBR disk

Applies To: Windows 10, Windows 8.1, Windows Server (Semi-Annual Channel), Windows Server 2019, Windows Server 2016, Windows Server 2012 R2, Windows Server 2012

Master Boot Record (MBR) disks use the standard BIOS partition table. GUID Partition Table (GPT) disks use Unified Extensible Firmware Interface (UEFI). MBR disks do not support more than four partitions on each disk. The MBR partition method is not recommended for disks larger than two terabytes (TB).

You can change a disk from a GPT to an MBR partition style as long as the disk is empty and contains no volumes.

Note

Before you convert a disk, backup any data on it and close any programs that are accessing the disk.

Note

You must be a member of the Backup Operators or Administrators group, at minimum, to complete these steps.

Converting using the Windows interface

  1. Back up or move all volumes on the basic GPT disk you want to convert into an MBR disk.

  2. If the disk contains any partitions or volumes, right-click each and then click Delete Volume.

  3. Right-click the GPT disk that you want to change into an MBR disk, and then click Convert to MBR disk.

Converting using a command line

  1. Back up or move all volumes on the basic GPT disk you want to convert into an MBR disk.

  2. Open an elevated command prompt by right-clicking Command Prompt and then choosing Run as Administrator.

  3. Type diskpart. If the disk contains no partitions or volumes, skip to step 6.

  4. At the DISKPART prompt, type list disk. Note the disk number that you want to delete.

  5. At the DISKPART prompt, type select disk <disknumber>.

  6. At the DISKPART prompt, type clean.

    Important

    Running the clean command will delete all partitions or volumes on the disk.

  7. At the DISKPART prompt, type convert mbr.

Value Description
list disk Displays a list of disks and information about them, such as their size, the amount of available free space, whether the disk is a Basic or Dynamic disk, and whether the disk uses the Master Boot Record (MBR) or GUID Partition Table (GPT) partition style. The disk marked with an asterisk (*) has focus.
select disk Selects the specified disk, where disknumber is the disk number, and gives it focus.
convert mbr Converts an empty basic disk with the GUID Partition Table (GPT) partition style to a basic disk with the Master Boot Record (MBR) partition style.

See Also