you will have to set the multiplier to 166 from the 133 you have now to increase your front side bus FSB since your CPU multiplier cannot go higher than 14x.
should start out at a CPU multiplier of 11 since:
and your default was 133x14=1862
once you are sure 11x166 works keep increasing your cpu multiplier by .5 til your system becomes unstable and back off 1 or 2 settings down. to test for instability you can run a very cpu intensive game like red alert 2: yuri's revenge.
you can also use a cpu test program, but i'm too impatient to wait that long and testing with actually games/ programs is still a decent way to find instability.
also check this info out: