Windows Media Player, WinAmp, RealPlayer, Quicktime and a few others. All of these programs are the most recent version. Also, the same effect happens when I try to play video games.
The only things that seem to work are YouTube videos on the Internet and .flv files on FLV Player 2.0. In addition, streaming audio from music sites such as Pandora.com seem to work.
It sounds like the sound chip on your card is fried. Did you have a power spike or lightning storm at the time? Did you handle the card without a ground strap?
Had anything changed on the PC before the problem occured? A new video card or something like that.