Several components are necessary to taking full advantage of high-definition programming on your home television; you must have an HD-capable television, you must subscribe to HD programming from your cable TV provider, and you must use a high-definition connection from your digital cable STB to your television.
Subscribe to high-definition programming. In most cases you must subscribe to HD programming from your cable TV provider at an extra charge before you will be able to receive any HD channels. Contact your cable TV provider and inquire about an HD upgrade.
Decide what type of HD connection to use. The two most popular HD connection types are component cables--a set of red, green, blue, red, and white cables--or HDMI, a single cable that transmits all audio and video data. HDMI provides better picture quality but is much more expensive. Your HD upgrade from your cable provider most likely will involve installing an HD-capable digital set-top box (STB). This HD cable or cables will connect your STB to your TV, so decide which type of connection to use, make sure your STB and your TV are equipped for that connection, and purchase the cable or cables.
Configure your TV for HD programming. Once the STB is connected to your TV via an HD connection, you will need to tune your TV to the corresponding input to receive a picture from your STB. It is also a good idea to configure your STB to match the highest-possible resolution your TV is capable of (720p, 720i, 1080i, 1080p, and so on). You are now ready to enjoy your cable TV service in true HD quality.