Hard Drive Not Recognized

Hello.

I am having trouble. My hard drive, a WD Scorpio 200GB, is not being detected in bios. AHCI mode is enabled. When I go into the Advanced BIOS Features, all the master and slave configs are none; however, my SSD is recognized as I am on my computer right now using it. I tried every SATA Port, EVEN THE SATA PORT MY SSD IS INSTALLED ON, and it doesn't work; I tried 2 different cables and still no recognition; I tried 4 different hard drives and still no recognition, so it is not a problem with my motherboard, hard drives, or cables. What should I do? I have been trying to figure this out for 4 hours.

Thanks!