Line-in and high pitched whine

I just hooked up my TV tuner on my video card. Basically for sound it said in th emanual to connect the line out on my video card to the line in on my sound card. Now all of a sudden if I turn up my volume there is a really high pitched whine. I checked cause if I mute line-in it goes away. It's bearable but if there is any way to get rid of it that would be great because sometimes if I'm listening to music and my volume is up I can hear it.

bad ground or exposed wire...or loose wire...u can overcome this by simply checking everything, or, turn down the LINE IN on the mixer...the input mixer, and put it at medium on the output mixer