Videos play correctly on computer but not on projector (black box)
PowerPoint video clips work fine on the laptop, but when connected to any digital projector, movie clips (AVIs and MPEGS) refuse to show on the projected inage, leaving only a black box where they should be playing, all the while the movie clips are playing perfectly on the laptop screen.
If that doesn't help, toggle the laptop to display the image on the external port only (in your case the projector).
To do this you normally press and hold the unique laptop key marked Fn. Then press the function key that selects internal/external/both video displays. This function key normally has either a single or double rectangle symbol (representing the video monitors). Then the video clip will be visible on the projector. The downside is you will see nothing on the laptop screen.
If you are using windows XP...double check Slideshow>Set up show>Multiple> Monitors is set to "Primary monitor". This option will be grayed out on systems with a single graphic card.
Or use a Desktop PC instead of a laptop as they do not have this problem.
The long fix - Things to try:
Change your Primary monitor in Windows
To do this right click your desktop then select Properties. The last tab should be Settings... click that... then click Advanced.
What you see next will depend on your particular graphics card/chipset/driver software, but look for a "Monitor" or "Adapter" tab. You're after an option to switch your "Primary" and "Secondary" output. By default most laptops are set to use the internal LCD as primary. Once you switch then hit "Apply" and "Ok" and get back to your presentation. Try it again... video is output to
your display for the audience... and you get a black box. Very annoying but at least your audience saw the video!
Try updating your graphics card drivers...or try an older version. Occasionally an old driver may work better than the latest, greatest.
First stop for drivers will be the laptop manufacturers site
If that doesn't help, try the chipset manufacturers site:
Next, visit Microsoft for Windows updates