Until a few minutes ago my computer was playing sound files perfectly fine. All of a sudden I can't play any sound anymore. I tried testing Windows sounds in Control Panel -> Sounds and Devices, but an error messages appears which says -
Windows cannot play the file %systemroot%\media\Windows XP Battery Critical.wav file. It may be damaged or may not be a valid sound file. Replace the file and try again."
Any idea what could have gone wrong?