A closed circuit television (CCTV) system includes a video camera connected to a TV with a recording device, such as a digital video recorder, connected in between. If you don't want the expense of buying a DVR to hook up to your system, you can convert a laptop to serve the same purpose for a fraction of the price. Buy an external TV tuner that connects the laptop to the video signal using a USB cable. The tuner disconnects in seconds when you need to take the laptop with you.
Eject the laptop's media tray to load the software disc that comes with the external TV tuner. Close the tray.
Click the on-screen buttons as each appears on your laptop to install the communications software for the external TV tuner. The software allows the laptop to process video signals from a connected device, such as a CCTV camera.
Plug in the USB cable from any available port on the laptop to the USB port on the edge of the external TV tuner.
Connect the audio-video cable from the jacks on the back of the CCTV camera to the matching jacks on the external TV tuner. If the camera does not record audio, connect only the video (yellow) cable to the external TV tuner.
Double-click the external TV tuner software to launch the application on your laptop. Click the channel button on the screen to set the TV tuner to the channel required by your CCTV camera, which is typically channel 3 or 4. You can now use the DVR features on the software to record surveillance video from the camera.