Can i upgrade the BIOS setting

My computer is about 4 years old. i am trying to install a PCI graphics cards and i need to disable the onboard video on BIOS. however, i do not see anything that says video, agp, or VGA on BIOS setting. I checked everywhere. I am wondering if my BIOS is an old version and i need to upgrade the BIOS software from manufacturers website. is there a such thing?