GPT (GUID) partition style

I want to format an external 3TB HD (2 1.5TB drives in a dual enclosure) in Vista 64 into the GPT (GUID)partition style. How can I do it so I can use the full 3 TB's? My only options ar NTFS and exFAT.

You can convert only empty, unpartitioned disks (raw drives or empty MBR drives) to the GPT format. To convert a volume that contains data, you must first manually delete the partition.

You can use the following methods to create GPT disks:
In the Disk Management console, right-click the MBR drive you want to convert to GPT and click Convert to GPT Disk. If the drive is not empty or contains partitions, this option is unavailable.

-OR-

In the DISKPART utility, select the drive you want to convert and enter the following command:
CONVERT GPT

For raw disks, you can use two additional methods:
After installing a new raw disk, open the Disk Management console to launch a wizard that you can use to configure the new disk. The wizard includes options to initialize the disk as MBR or GPT.

-OR-
Initialize the new disk later by using the Initialize Disk option in the Disk Management console.

Let me explain. I first, by mistake, formatted the drive as a MBR format and then realized I could not access the 3TB's I wanted. So, I reformatted the drive on my Macbook Pro laptop in the GPT partition style. I now have a drive which shows up on my Vista 64 PC in disk management as a 200MB Healthy (EFI System Partition), New Volume 2794.21GB NTFS Healthy (Primary Partition), 128MB Unallocated. I want a single partition of 3TB's. How do I do it? Thanks for your help.....

What is the problem in using 3TB space with MBR format? The main drawback to a GPT formatted volume is that you cannot boot from it unless you have a machine with an EFI BIOS.

I thought that the MBR format could not utilize more that 2TB's.