The external hard drive is not detected.

The GUID Partition Table (GPT) provides a more flexible way for partitioning disks than the older Master Boot Record (MBR) partitioning scheme that was common to computers.

NOTES:

• This procedure not only removes the drive's partition, but also removes the Drive Signature.
• You must open Disk Management and document the Disk Number of the drive containing the GPT Protective partition, as you will need this information during the process.

WARNING: There is a risk of data loss. It is highly recommended that you backup all critical data on the drive before proceeding.

1. Press the Windows Logo + X key combination on the keyboard.
2. Click Disk Management.
3. Locate the drive that is identified as GPT.
4. Press the Windows Logo + X key combination on the keyboard and select Command Prompt.
5. Type diskpart and press Enter. The diskpart prompt will open.
6. Type list disk, then press Enter.
7. From the list of disks locate the GPT drive.
8. Type select disk then the number of the disk (Example: select disk 0).
9. You will return to the diskpart prompt.
10. Type clean and press Enter.
11. The drive's partition and signature will be removed.
12. From the diskpart prompt, type exit and press Enter.
13. At this point, the internal or external drive can be re-initialized, partitioned and formatted.
14. Press the Windows Logo + X key combination on the keyboard.
15. Click Disk Management.
16. Right-click on the disk in question and select Initialize Disk from the drop-down menu. Once the drive is initialized, continue using Disk Management to partition and format the drive.