HOW TO: Change a GUID Partition Table Disk into a Master Boot Record Disk in Windows Server 2003

This step-by-step article describes how to change a GUID partition table (GPT) disk into a master boot record (MBR) disk (64-bit only) in Microsoft Windows Server 2003.

Important You can change a disk from GPT to MBR on an Intel Itanium-based computer, assuming that the disk is empty. Make sure that you back up all your data and delete all partitions and volumes before you convert the disk.

How to Change a GUID Partition Table Disk into a Master Boot Record Disk

You can change a GPT disk into a MBR disk either by using Disk Management or by using the command line. To do so, use either of the following methods.

Use Disk Management

1. Click Start, point to Administrative Tools, and then click Computer Management. Alternatively, open the Microsoft Management Console (MMC) that contains the Disk Management snap-in.
2. In the console tree, click Disk Management.
3. Right-click the GPT disk that you want to change into an MBR disk, and then click Convert to MBR disk.

Use a Command Line

1. Click Start, and then click Run.
2. In the Open box, type cmd, and then click OK.
3. At a command prompt, type diskpart, and then press ENTER.
4. At the diskpart command prompt, type list disk, and then press ENTER.
5. Make a note of the disk number of the disk that you want to convert to an MBR disk.
6. At the diskpart command prompt, type select disk n (where n is the number that you recorded in step 5), and then press ENTER.
7. At the diskpart command prompt, type convert mbr, and then press ENTER.

Notes

• You must be logged on as an administrator or as a member of the Administrators group to perform these procedures. To perform these procedures remotely, you must be a member of the Administrators group on the remote computer. If your computer is connected to a network, the network policy settings may prevent you from performing these procedures.
• Itanium-based computers support both MBR and BPT disks. However, x86-based computers support only MBR disks.

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.

For additional information about how to use Disk Management to manage basic and dynamic disks, click the following article number to view the article in the Microsoft Knowledge Base: