My webcam isn’t working right

My webcam isn’t working right now. I put a tv card in my computer, now the only input the webcam software will take is from the tv card. I have to play around with it. Then I installed windows xp and the drivers for the tv card don’t work. Now I have lots of stuff that doesn’t work. It is convenient to be able to turn on a news broadcast or something when you’re working at the computer.