HOW TO: Use the Diskpart.efi Utility to Create a GUID Partition Table Partition on a Raw Disk in Windows


This article describes how to create a GUID partition table (GPT) partition (where GUID is the abbreviation for globally unique identifier) on a raw disk by using the Diskpart utility (Diskpart.efi).

Create a GUID Partition Table Partition on a Raw Disk

To create a GPT partition on a raw disk by using the Diskpart utility:
  1. At a command prompt, type: diskpart to start the Diskpart utility: "Diskpart version 0.0" is displayed as well as a Diskpart prompt.
  2. At the prompt, type: list to list the mounted hard drive volumes.
  3. At the prompt, type: select x (where x is the number of the hard disk drive that you want to convert to GPT). The following information is displayed: "Selected Disk = x".
  4. At the prompt, type: new gpt to add the GPT information into the non-volatile RAM (NVRAM).

    NOTE: This step does not create the GPT partition information.
  5. At the prompt, type: create name="efi system partition" type=efisys Size=102 to create the Extensible Firmware Interface (EFI) partition.

    NOTE: The name can be anything you want, but if the name has spaces in it, the name must have quotes around it. The type must equal either Efisys, Msres, or Msdata. If a size is not specified, the partition uses the remaining unpartitioned space. To install Windows XP, the Msdata partition must contain at least 2 gigabytes (GB) of free space.
  6. At the prompt, type: create name="microsoft reserved" type=msres Size=31 to create the MSR partition.
  7. At the prompt, type: create name="basic data" type=msdata to create a partition for the remaining unpartitioned space.
  8. At the prompt, type: inspect to display the partition information.
  9. At the prompt, type: exit to quit the Diskpart utility.

Locate the Diskpart Utility

To locate the Diskpart utility:
  • If Windows XP 64-Bit Edition is installed, the Diskpart utility (Diskpart.efi) is found in the Msutil folder on the EFI partition of the first hard disk drive.
  • If the hard disk is raw, use another computer to expand the \IA64\Diskpart.ef_ folder from the Windows XP CD-ROM to a floppy disk or LS120 disk.
The definitions of the GPT-type partitions are:
  • Msres: The Microsoft reserved partition for feature support that is used to convert a basic disk to dynamic.
  • Efisys: The EFI system partition that is required for boot operations.
  • Msdata: The user data partition that is used by Microsoft Windows.


Article ID: 297800 - Last Review: Oct 21, 2008 - Revision: 1