Using a projector attached to your computer during a presentation makes it easy for everyone in the room to see your material. When you aren't using the projector for presentations, you can use it to watch movies or play video games you have on your computer. Just find a screen or an empty piece of wall and you're all set.

Connections

Make sure that the computer and projector have at least one video connector in common. Most computers have a VGA or DVI port; some have both. Laptops may also have an HDMI port. Projectors usually have these ports and some designed for video sources such as component video and S-Video. You just need to take cable length into account. HDMI cable doesn't perform as well if the cable length is over 15 feet.

Resolution

Verify that the projector supports high-definition resolutions. Some of the less expensive projectors support only up to an 800x600 resolution. Take the projector's resolution into account when designing slides; otherwise the image won't fit in the screen or it will be forced to fit while losing some of its details.

Sound

Use the necessary audio cables. HDMI cables support both video and audio, any other connection requires separate audio cables.

Aspect Ratio

Make sure that the projector supports the same aspect ratio as the computer. The trend in computer monitors is toward a 16:9 widescreen aspect ratio. This is the same ratio as HDTV screens. Some projectors support only the 4:3 aspect ratio of standard definition TV. This is an issue only if you are showing video recorded in a 16:9 aspect ratio.

Remote Control

Use a separate USB connection between the computer and projector if you are going to use a remote control for slide shows.

Source:

University of Wisconsin, River Falls: setting up a laptop computer and LCD projector

More Information:

Infocus: Setup guide for a PC laptop computer