I'm slightly confused. You state you created a system image on a 250 GB hard drive, but then state that the drive you put it on was a 2 TB hard drive. If the image is on a 2 TB hard drive and you didn't allocate the rest of the space, then you should be able to use Disk Management, or a similar utility depending on OS, to allocate the unused space as a separate partition or expand the existing 250 GB partition to fill the 2 TB, minus whatever is needed for journaling, MBR, etc.