How to Remove a GPT Protective Partition

On a WinXP box, I recently popped a harddrive that I was planning to install an OS onto into the external eSATA bay I use for backups and such. My plan was to blow away any partitions to make it easier to distinguish from the other drives in the desitination system during the install.

Unfortunately, the Disk Management utility didn't know what to make of the drive. It was listed, but all options wee greyed out. In the partition area, it said it was a "GPT Protective Partition".

After googling around for a while, it became clear that XP didn't know how to talk to such partitions and the solution (asuming you didn't care about the dat on the disk) was the following:

• Open a Command Prompt window.
• Enter "diskpart". This will start the the DiskPart utility.
• Enter "list disk". This will display all drives in the machine with a number beside them.
• Enter "select [number]" (where "[number]" is the number next to the disk you want to nuke), for example: "select disk 3".
• Enter "list disk" again. Verify that there is an asterisk next to the drive you selected above.

WARNING: The following command will destroy all data on the disk. It will not prompt you or warn you. It will just wipe the drive with extreme prejudice. It is irreversible. Scared enough? Good.

• Enter "clean". When it is done, it will tell you that "DiskPart succeeded in cleaning the disk."
• Enter "exit" to exit the DiskPart utility. You can now close the Command Prompt window.
• Go to Disk Management under Computer Management. The disk you just wiped will now be listed as "unknown". Right-click on the disk info block (to the left of the partition area), and select"Initialize Disk". Confirm that the correct disk is selected in the pop-up and press "Ok".

You can now create a partition on the disk (right-click on the partition area).

Applies to: Windows XP