Do you have it plugged in correctly? Power and data cable attached?
Looking up your motherboard I'm not sure you'll ever get this working. From what I've been told, the Via KT600 chipset can't run the SATAII drives. Even if you jumper them for SATA I operation it simply won't work. Make sure you have the jumper on the drive that limits it to SATA 1.0 speeds. But if what I was told is right, you need a different hdd. (SATAI drive to be exact.)