Make sure the 16 bit version of QuickTime is on your hard drive.
See QuickTime Installation.
On some monitors, in order to maximize the size of the screen being used by our program, the setting display should be 640 x 480. If your Windows video display settings are at a higher resolution, the program may not appear full screen.
For the best audio results, the volume setting of your internal speakers should be maximized.
Should the video become jerky or out of sync with the audio during the program, press the pause button then return to play and the problem will be eliminated.
Screen savers should be deleted to optimize performance. If a screen saver is not deleted, it should at least be set not to enable for two minutes so that it is not engaged during the program. Some screen savers interfere with QuickTime and will not allow the playing of the video.