Working with the 64-bit edition of Windows XP Professional affords you some additional disk-management considerations above and beyond those found in the regular 32-bit Windows XP Professional version that most of us will be using. Itanium-based systems running Windows XP 64-bit Edition can make use of a new partitioning style called the Globally Unique Identifier Partition Table, or GPT for short.
GPT disks have the following features, which are unavailable on any other version of Windows XP:
GPT disks can support partitions up to 18 exabytes in size.
GPT disks can support up to 128 partitions per disk.
GPT disks do not contain a standard system partition; instead they reserve 1% of the total ...