Klownin79,
Look at the partition table and available space with PMagic, FDISK, Win2K admin tool or something. If the space is there then maybe it is not partitioned, or belongs to a partition but is being used by some gigantic hidden file, or just and simple the partition is not formatted (and the data underneath happens to be valid for a FAT32 30Gb partition or so).
If space is not phisically there, then look at the S/N of the drive and check into the manufacturer's site that you have the drive you are supposed to.
Failing all of the above, your drive could have been configured by default with an 'adressing' mask to solve old bios compatibility problems by hiding parts of the available space. You will have to check with manufacturer, but I can tell you for instance that IBM hdds allow for this through the Drive Feature Tool disk.
Regards
FTC