Convert a gpt protective partition

I recently put a 64 bit Vista formatted Drive into my XP HTPC box and found it was unreadable and could not be formatted.  Computer Management displayed the drive as a GPT Protective Partition. Unfortunately Windows XP cannot read or write this type of filesystem let alone mount the drive. A GPT disk uses the GUID partition table (GPT) disk partitioning system.

Your Options are:

or Using the Windows interface

Windows XP Disc support Windows FAQ.