This is an emachine computer? If so then the BIOS are probably locked to prevent overclocking. Nearly all OEMs do this, Dell, HP, emachines ect. They want you to buy a faster computer not overclock the one you have! Also they buy parts that are "good enough" but not good enough to overclock where extra voltage and heat stresses components.
so what would be a good oc with this cpu if i run it at 3.4 ghz it seams slower than and battle field 3 runs funnny and my score doesent go up from a 6.3., i disabled amd cool and quiet and turned fans on while booting then speed fan takes over and with the radon 5670 1gb graphics card wont auto tune any more with the driver updated it would go to 850 on its own now it just stays at 775 stock
i would just go back to stock settings and leave it that way. although you can oc your fsb a little its not going to be worth it. the only thing that might make your game play better is to tweak your os and disable a lot of stuff. do a search for blackviper os tweaks, he has a guide posted that may be useful. good luck