I just got a new slave drive for my brand new pc I built. I currently have a SSD to hold my OS and to boot up with, but for some reason it only shows one hard drive which is my SSD. In device manager it shows my second one but won't come up under Hard Disk Drives list.
assuming you're running Windows XP Vista or 7 here. You have to go into the disk manager and initialize the disk. It will show it there with filesystem type of RAW right click click initialize then after that you can create partitions,format them and use your new HDD.