Deltona, SATA is often not mentioned in the BIOS boot order. Enable everything and disconnect everything else to be certain. But at this point I doubt that's the problem.
What drive model is it? You may be running into an SATA 3Gbps issue with your motherboard. Some are 3Gbps "compatible" once Windows drivers are loaded (or the BIOS is updated) but have issues fully recognizing and booting a 3Gbps drive. Try installing the drive's rate limit jumper. Performance won't suffer; 1.5Gbps is more than your drive can supply.
You may have to ID the motherboard to see if there's an updated BIOS that would help. Of course, that's if you want to make it work.
