I think there is a way round it, and I know what happened, but I may explain it badly.
You imaged a hard drive partition of 160. When you restored to the larger drive, my Paragon H D Suite 2008 offers the choice of make the partition, or make the drive (something like that). You chose partition, so it made as close a replica in size. If you'd chosen drive, it'd fill out the whole of the disk.
(I'm not sure if Drive Copy has as many options as the H D Manager, so it's all very well me saying this - you may not have that as an option)!
So, you are left with an unused portion (about 90Gb) on your new drive. I don't think Drive Copy is likely to have a "merge partitions" option, but some magazines have recently had copies of both Paragon and (? memory failure) that do.
If you can get one of these, it's an easy job to merge the two partitions and go back to one drive of 250Gb.
However, I'd claim back that 90Gb as a separate drive, and use it for data storage. Easily done in Windows.
Right click on My Compute icon on desktop, chose Manage... Choose Disk Management option towards bottom left.... There is a graphical representation of your HDD, with the 160Gb partition visible, and the remainder unformatted, and possibly unpartitioned. Right click on it, and you can format it, and gain the space.
Hope this helps. Tired, and full of hayfever, so may not be as precise as I'd like.