Can you over clock all computers?

I just build a computer a few months ago and I used an Athlon II X3 3.2GHz and an ASUS M4A78LT-M LE motherboard. I have been into the bios of it and I cant find any options to change the FSB or anything to do with over clocking. And does it depend on the motherboard, which is where the bios is I think or does it depend on the processor if you can over clock or not?