totally agree with purple stank and warmacblu
this machine is seriously old
that board support only ddr which costs 4-5 times more than ddr3
you can get a motherboard (like asrock n68c s ucc in which you can play old games like gta San Andreas, prince of Persia 1,2,3,sands of time,the 2 throwns, nfs most wanted etc without any graphics card) that support ddr3 and amd phenom 2 in cost of 1gb ddr ram
so do not upgrade just build new one with ddr3 support
if your budget is low you can consider amd as processor otherwise go with intel core 'i' series