I know this time its because of a glitch. But if it happens at other times you may have turned off your touchpad by mistake! lol! yep done that too! Thats of course if you are using a laptop. If this happens, go to the bottom right hand corner of your screen and gently use your arrow to run along the signs such as battery, google desktop signs and so on. When you get to touchpad, right click and follow the instructions!