Yeah, find out what type drive it is and go to thier websites to check the jumpers. If you don't know what jumpers are, on the back of the drive there are little metal pins, some for the cable, and then a set of others that usually have two small plastic jumpers (shaped like little black rectangles). The jumpers fit over the pins and connect them in certain ways. There's usually three setting, master, slave and CS? I think the third one is CS. Anyways, if you have two disk drives, they need to be set in certain ways. Your main hard drive will be the master, and the new one will be the slave. (I think I'm getting this right, someone correct me if I'm wrong). So you need to find out how to set your jumpers to make the new drive have a slave setting, and the main hard drive a master setting, and evrything should work.
Ok, someone correct me if i missed anything, its been a while