The presentations use Microsoft Media Player or Java depending on your computer's operating system.  The bottom of the screen is similar to any VCR control panel, with "PLAY" triangle, "PAUSE" (II) when in play mode, "STOP" which is a square box and "FAST FORWARD/REVERSE" triangles.

 The best way to view the show is to click the Maximize DOT (top right on “Windows” or the green button on a Mac top left.) after the slide show starts (mouse double tap works on Mac).  If you wish to view the slides slower, you can click on the "PAUSE" button, then move the slider on the bar above the control button area by clicking just ahead of the slider box on the bar (or behind to view the previous picture).