To reset the TVGuardian SD, simply disconnect it from its power source for 10-15 seconds and then reconnect. As soon as you reconnect the unit to its power source, press the "TVG" button on the TVGuardian remote 5 times. Then press "SEL" button once. A brief screen should show up saying the units been reset. You may need to repeat this process several times to get the timing right and for the unit to properly reset.