media files lockup (.avi, .mpg, .wav)

Whenever I attempt to run a media file (.avi, .mpg, .wav, etc.) on my system it fails to open. If I attempt to close the player the PC locks up and I have to power it off. This happens with all types of media players. System info: win98, IE 5, MediaPlayer 7, Kazaa, RealPlayer. Thanks, Wayne 😉