What is GPT disk?
The GPT is short for GUID Partition Table, introduced
as part of the Unified Extensible Firmware Interface (UEFI) initiative. GPT provides a
more flexible mechanism for partitioning disks than the older Master Boot Record (MBR)
partitioning scheme that was common to PCs. Learn more…
GPT Protective Partition issue
Symptom: When you plug Windows XP 32-bit Operating System with an internal or
external hard drive, the data on drive is inaccessible and in Disk Management it
recognizes the disk as a GPT Protective Partition. Right-click on it, there is no
available options in the drop-down menu. In other words, the drive cannot be
partitioned or formatted under the circumstances.

Reason: The internal or external hard drive was previously configured
as a GPT partition in either a Windows or Macintosh computer. Because 32-bit version of
Windows XP cannot read, write, and boot from GPT disk. It will only see GPT Protective
partition (the Protective MBR). The EE partition will not be mounted or otherwise
exposed to application software.
Solution: Diskpart command-line utility is a traditional way to access GPT
Protective Partition by removing GPT disk from the current in-focus disk, however,
it is a data destructive process. Nowadays, AOMEI Partition Assistant Professional allows you to
access GPT Protective Partition by converting to MBR partition and ensure data
integrity.
Convert GPT Protective Partition to MBR partition without data loss
The following instruction provides the steps to change a hard drive connected in an
existing Windows XP 32-bit Operating System from GPT Protective Partition to MBR
partition while keeping data safe.
Note: MBR disk supports only four partition table entries. Therefore, the
solution only applies to the hard drive previously configured as at most four GPT
partitions.
Step1: Install and run AOMEI Partition Assistant Professional. Then, click "Convert to MBR Disk" in the left navigation.

Step2: In the pop-up window, click "OK" to convert disk from GPT to
MBR.

Step3: Click Apply and Proceed to commit operation.

Step4: The operation requires rebooting. After restarting computer, you
will find "GPT Protective Partition" issue has been solved. You can access data from the
partition again.

Apart from the conversion from GPT disk to MBR, AOMEI Dynamic Disk Manager also allows
you to resize dynamic disk, extend dynamic system volume, expand/shrink/move dynamic mirrored
partition, convert dynamic disk to
basic and vice versa, add drive to software
RAID 5, remove drive from software RAID
5, move volume slice, etc.