No.120
Computer fans typically use a control method a little different from just a DC motor. Usually a fan contains at least three signals: PWR, GND, and PWM. PWR and GND are usually 12 and 0 volts, though I think there are 5V fans. The PWM signal is set at a constant frequency around 20 kHz and the duty cycle determines the fan speed.
So break out a 555 chip if you want to build a fan control circuit, or you could use another method of generating a high speed PWM signal.