|Do you have DDR2-800 RAM? Decent power supply with plenty of amps on the +12v rail? Which X2 4200+ do you have? There were at least 3 for the socket AM2. Different voltage requirements, different wattages, different core revisions. Not all CPUs overclock equally.|
Most of the overclock settings are in the M.I.T. menu in the BIOS. Since you have an PCIe video card, make sure all options for the onboard graphics are disabled.
- lower the HT Link Frequency so that it doesn't over-overclock as you overclock the CPU & memory
- disable Cool'n'Quiet & lock the PCIe frequency at 100MHz
- the CPU Clock Ratio *may* have to be lowered (it can NOT be raised higher than the default)
- enable the CPU Host Clock Control to be able to adjust the CPU Frequency
- set "Set Memory Clock" to manual, then you can adjust the memory clock
Do you have a copy of the manual?