BIOS Upgrade. I have a Mesh PC fitted with an ASUS ATX Micro NForce 4 939 PCI motherboard. I have

Question

I have a Mesh PC fitted with an ASUS ATX Micro NForce 4 939 PCI motherboard. I have just replaced my AMD Athlon 3500 chip with an AMD Athlon X2 4200, which runs fine. However I have heard that one can get a BIOS update that will make the most of the new chip. Is this correct and if so, where can I get it and what is it called?