1. In bios, set Sata as Ide for On chip sata type within Advanced settings menu.
2. You may need to format the drive for it to be detected.
3. See if all three devices ( the two HDDs and the optical) show up in boot order in bios. You'll find that under Standard (cmos) settings.
You can also hit F12 during boot to bring up a boot menu which will show you which drives are being recognized.