Unplugging (shutting off) still goes a long way toward fixing some confounding, but more simple computer problems. Before spending oodles of time or waving the white flag of surrender, shut off the computer (laptop OR desktop) using the power button if you cannot shut it down the normal way using your mouse or track pad.
You WILL have to hold that button down about 10-20 seconds, much longer than when you turn it on. Make sure ALL the lights go off on the computer. Give the computer 10-20 seconds of OFF before pressing the power button to turn it on again. If it comes back on, put away that surrender flag and go about your computing. If it does NOT behave as usual, then make a call to your favorite Tutor.
ALWAYS REMEMBER: before calling for help - is it plugged in, and is it turned on?