Bios Says CPU is Overclocked when I change Multiplyer

[Browndog]

I have an Epox 8Kta3 when I change the Default voltage of my Duron 750 to 1.8, the System give an error message "CPU overclocked Fail" and the multipyer change dose not take effect.

[Phil]

have you unlocked the duron yet?

[Browndog]

Yes I have and it work before I cahnged the default CPU voltage

[oc jason]

Sound like that for some reason that the board or the chip sont wanna handl the voltage-check to make sure that you dont need a voltage mod