Window Mode allows you to zoom in and out and to pan when the movie image is bigger than the window size. With the mouse in Window mode, you toggle the mouse between zoom, pan up/down, and pan left/right by pressing the spacebar or continuing to press F8. With the mouse in zoom mode (the cursor looks like a magnifying glass), you can make the image bigger by clicking the left mouse button and make it smaller by clicking the right mouse button. In zoom, a mouse thumbwheel will scroll the image right/left.