Convert an MBR disk into a GPT 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). 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).

You can change a disk from MBR to GPT partition style as long as the disk contains no partitions or 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 the data on the basic MBR disk you want to convert into a GPT disk.

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

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

Converting using a command line

Use the following steps to convert an empty MBR disk to a GPT disk. There's also a MBR2GPT.EXE tool that you can use, but it's a little complicated - see Convert MBR partition to GPT for more details.

  1. Back up or move the data on the basic MBR disk you want to convert into a GPT disk.

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

  3. Type diskpart. If the disk does not contain any partitions or volumes, skip to step 6.

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

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

  6. At the DISKPART prompt, type clean.

    Note

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

  7. At the DISKPART prompt, type convert gpt.

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 disknumber Selects the specified disk, where disknumber is the disk number, and gives it focus.
clean Removes all partitions or volumes from the disk with focus.
convert gpt Converts an empty basic disk with the Master Boot Record (MBR) partition style into a basic disk with the GUID Partition Table (GPT) partition style.

See Also