Why can't I use my SATA link as the harddrive that runs my OS?

Answer 1

You are probably using SATA alongwith an IDE drive. IDE precedes SATA in Boot preference.

So now , Try to remove the IDE Hard Drive and boot. If this does not work...

Look at your BIOS setting and keep your motherboard manual handy. You might have to enable the SATA bootable drive as boot first boot device in BIOS. If you can succesfully configure your BIOS, it means you can use both types of drives without any problems. So you may not have to worry bout loosing your IDE drive.
Give me more info if you think this is the wrong direction I have fired in.