At first, try a small overclock to see if your system is stable. Your CPU has a multiplier of 9 and a bus speed of 266 that is quad pumped (4 X 266) to a front side bus speed of 1066. I'm suggesting you try to raise your bus speed from 266 to 333 which will raise your CPU frequency to 3.0 Ghz (9 multiplier X 333).
Go into your BIOS, AI Tweaker Menu Screen, set the item "AI Overclock Tuner" to manual.
Set the FSB frequency to 333. Save BIOS andf boot to Windows. Runs tests for stability. Depending on results, you may need to adjust CPU voltage.
Mind you, this is a very simple attempt with no adjustments to RAM, RAM voltage.