One of many parts that are machine specific/proprietary.
Look here http://www.hauppauge.com/ for a USB tuner. I have this one http://www.hauppauge.com/site/products/data_hvr850.html
My 26-month old HP Pavilion dv9334us died, from the motherboard failure now apparently extremely common in the HP Pavilion line. So I went out and bought a Dell Studio. With the HP had come a "HP express card Digital/Analogue TV Tuner". When I insert it in the card slot in the Dell it is recognized as a multimedia card. But I can't find drivers for it. The HP-provider drivers (found on the HP downloads site) apparently check to see if they are installed in an HP machine. Is there a way to use this card in another brand of computer?