How to Hook Up a Video Projector to My Laptop & Switch Screens
- 1). Plug in all devices but make sure they are not connected or turned on.
- 2). Plug the VGA cable into your laptop underneath the icon showing the small screen. Connect the cable to the "in" port at the back or side of your video projector.
- 3). Turn on the projector and let it warm up. Most projectors, especially older models, need a minute or two for the fans to begin operation.
- 4). Turn on your laptop computer. After the laptop has recognized the video projector you will be given the option of displaying information only on the laptop screen, displaying the same information on both screens or only displaying information on the video projector. You can manage these options using the FN and F5 keys.
Source...