You might need to do this if...... You have disconected the battery.Something has stopped the window in it's normal travel.It just decides to loose it's memory. Normal operation..... (Models with electric windows) When you press the window switch in either direction to the stop the glass will automatically lower or raise to the end of it's travel. To reset it..... With the window fully up, press and hold the switch firmly in the down position untill the glass reaches the bottom, continue to hold for two seconds.Firmly press and hold the switch in the up position untill the glass reaches the top, then continue to hold for two seconds. The window should then opperate correctly.