Your mobo is a weak link there,
I think I had a similar if not the same model a while back and couldn't do anything in bios, no software supported the chipset to do it that way either,
your best bet imo is grab a cheap 770 chipset board and put the chip in that, AsRocks M3a770de is a solid choice and cheap as dirt these days, but scooch about for Am3 Motherboards, (minimum of a 700 series chipset)
you'll want 4Gb of ddr3 as well but that is cheap these days too,
thats the bare minimum to get you overclocking,
Moto
------------------------------Once you start watercooling, you are almost automatically inducted into the modding circles as well, because theres rarely a 'from the box, fits everyone' solution, its your ingenuity and resourcefulness that makes it all happen, Reply to Motopsychojdn
For $60-70 your can get the Biostar A880+ (http://www.newegg.com/Product/Product.aspx?Item=N82E16813138283) motherboard to unlock the fourth core, if your currently using onboard graphics, it will likely be an upgrade for your gpu as well.
but youll also have to upgrade to ddr3 ram for this motherboard, which i recommend Gskill DDR3 x2 sticks of 2gb ddr3 ram
(http://www.newegg.com/Product/Product.aspx?Item=N82E16820231396)