Windows XP pro Critical Stop Sound.

My computer started to making a sound (BONG) evevy once an a while. After cheching the sound alert setting it was the sound for a critical stop. I get no on screen message just this sound(BONG). There no timing to it. I,ve change me sound setting but I still get that sound. It overrides any ofter sound I’m playing(i.e. music). The only I’ve have got it to stop was to turn off my sound card. It’s driving me NUT’S. Any help would be thankful. Guy