You also may need to modify existing presentation files if you created them for a different resolution. See your software documentation for specific information.
Make sure your computer’s resolution setting is correct. Ideally, it should be 1280 x 800 to match the projector’s native resolution for the PowerLite 826W, or 1024 x 768 for the PowerLite 825 or 85. If this option isn’t available, select one of the other compatible video formats.
Check the projector’s Resolution setting. Select Normal or Wide, depending on the size of your computer’s display panel.