Overclocking E4400 And GALAXY GeForce 9400 GT

^^at stock volts u can easily oc any modern processor to 4-500Mhz more but u need to keep a check on the temp & run stability tests at any stage the temps should not cross 65-70C
also give small increments like 10-20Mhz then run the tests & carry on
For the Gpu try msi afterburner