Instructions
Purchase the correct cables. If you have an Xbox 360, you will need the Xbox 360 VGA HD AV cable to connect it to a VGA PC monitor. To connect it to a DVI input, you will need a component to DVI adapter. The Wii/PS3 VGA HDTV AV cable will work with both the Wii and PS3 on a VGA input. To connect the Wii to a DVI input, you will need the Wii component cables and a component to DVI adapter. To connect the PS3 to a DVI input, you will need an HDMI cable and an HDMI to DVI adapter.
Connect the cables. Plug in any adapters to the VGA or DVI port on your PC monitor and connect them with your video game system using the proper cables. Some adapters may require a power supply, so be sure to plug that in as well.
Turn on your video game system and setup your resolution. Since your PC monitor will have a different native resolution than your video game system, you will need to adjust the settings for the best performance. The Xbox should be able to output 1080i, the PS3 1080p and the Wii 480p.