VR-Zone has done up a guide on how to modify the GeForce4 MX card to a Quadro4 by re-positioning the resistors to change the device ID. After numerous trials and errors, we have finally found the correct resistor positions which turns the GeForce4MX to a Quadro4. Upon rebooting, the card is recognized as Quadro4 550XGL!

VR-Zone NVIDIA GeForce4 MX To Quadro4 MOD