Only part of the computer image displayed. What should I do?

• Press the Auto button on the remote control. Make sure the image Position setting is correct on the Video menu.
  
  Make sure your computer's resolution setting is correct. Ideally, it should be 1024 W 768 to match the projector's native resolution. If this option isn't available, select one of the other compatible video formats listed on page 120 of the user's guide.
  
  Windows:
  Right-click the desktop, select Properties, click the Settings tab, and select a different resolution.
  
  Macintosh OS 8.6 to 9.x:
  On the Apple menu, choose Control Panels, then click Monitors and Sound. Select a different resolution.
  
  Macintosh OS X:
  Open System Preferences, double-click Displays, and then select a different resolution.
  
  You also may need to modify existing presentation files if you created them for a different resolution. See your software documentation for specific information.