Sorry for the late reply.
Okay, you have mismatched RAM, but you should be able to do it.
1. Set your RAM timings to 4-4-4-12. It is currently doing 4-3-3-9. I do not have experience/knowledge with your board/BIOS, but look for RAM timings/adjustments.
2. Set the RAM voltage to 1.8V. If you only get choices of "normal" and "+0.1V, +0.2V", etc., set it to normal.
3. Set the FSB to 266MHz.
4. Check your RAM speed after putting the FSB to 266MHz. If your RAM speed is HIGHER than 266MHz, see if you can adjust it. If not, and it's higher (like at 333MHz), adjust your timings again (as you did in the first step) to 5-5-5-15.
4. I'm not sure what you voltage is set at now (I can see what CPU-Z shows, but not what it's set at). I'm going to guess ~1.35V-ish. Try setting the CPU voltage to ~1.3625V. That is a 65nm CPU so they can take a bit more voltage.
5. Report back about it went?
This will net you a 2.13GHz clock speed if successful. I see you're at 1.8GHz so you're just under halfway there already. Your board is only rated for 533MHz FSB speed, so going higher that it's rated, especially on a budget board, is a gamble and will involve more work, like more RAM tweaking, Northbridge voltage, etc. The next step would be to try a 300MHz FSB (2.4GHz result) and then a 333MHz FSB (2.66GHz result, which is a healthy ~1GHz+ overclock over stock). Again, the boar, and how it sets your RAM (ratio and timings) is what you're mostly at the mercy of. That's the trade-off with budget boards. The CPU, almost for sure, can do it.
Just monitor temperatures (try to stay below ~65C maximum), and make sure the CPU stays under ~1.45V, and the RAM under ~1.9V (not sure what that stuff can take as it seems generic), and you shouldn't damage anything.
Edited by Princess Garnet - 5/20/11 at 8:53am