An option setting device and method is provided for use on a computer mother-board for providing various user-defined settings to the motherboard. The motherboard includes a CPU, a chip set coupled to the CPU, a clock generator coupled to the chip set, a delay circuit coupled to the chip set, a first latching circuit coupled to the chip set, and a reset circuit coupled to the delay circuit. After the motherboard is power on, the CPU transfers a first setting via the chip set to the first latching circuit so as to allow the first setting to be latched in the first latching circuit, and meanwhile triggers the delay circuit to start counting time. The delay circuit outputs a trigger signal to the reset circuit after a preset time, causing the reset circuit to restart the motherboard. After the motherboard is restarted, the chip set fetches the first setting from the first latching circuit so as to be set accordingly. In the case of the motherboard further having a voltage regulator, the option setting device and method further utilizes a second latching circuit for latching a second setting from the CPU and then transferring the latched setting to the voltage regulator to cause the voltage regulator to output a voltage accordingly.