Hook computer to TV?

you need to buy an input card or a tv tuner to do that...

I can not help you very much, as each Video Card Model is Different.

You should Check the Leads, Computer's Output and TV's in. usually it's a Yellow Phono socket for both ends. Allthough S-Video has been seen.

The Best thing to do is to read the Video card's Instructions, they should tell you how to use set it up. Sometime you need the drivers from the Video Card company. You need to know what you've got as each Model may have different drivers.

To use a TV as a Second Screen, you should go to Control Panel -> Display -> Setting (The far right) and activate the second Screen. Your TV may start working.

Some Video Cards May not Allow TV and Monitors on the Same Computer. And Some European TV's don't Display 60Hz, which is the US standard.

Ok, first off, i'm assuming you are using an S-video cable to connect your computer to your tv? If so, switch through the inputs on your tv. It will show up automatically once you hit the correct input. If you are using the 3-split cable, ensure you have all the cables plugged into the correct corresponding colors (same method applies to the TV, check your channel input). You may want to check the manual on your graphics card. If your card supports the feature, it will tell you how to use it.

depends on the brand of computer or graphics card..we need more details.