In the 'Start' menu select 'Control panel', then 'Sounds and multimedia'. On the 'Hardware' panel double-click 'Audio codecs' and choose the 'Properties' panel. A list of available codecs will appear.
Two mp3 codecs should be there at least: Frauhoffer and Creative (ctmp3.acm). Double-click the ctmp3.acm and change the priority to the highest available. After accepting, the ctmp3.acm codec should appear at the bottom of the codecs list. The sounds should be played correctly now.