Didn't your hard drive come with a installation disk, 3.5"? I just bought a hard drive with and the disk has a utility to copy your old hard drive over to the new one.
Get a copy of ghost if you can. Temporarily disconnect your CD drive then connect the new drive as primary master, the old drive as secondary master (or whatever your CD was). Use ghost to copy the contents of your old drive to the new drive. Of course if you have virii on the old drive they'll be on the new one also.