do the following:-
1.chk if ur spkrs are loosely connected to ur machine.
2.click on the volume icon in d system tray n chk if nything is muted.
3.change the socket for the spkr's power cord.
4.also chk 'sounds & audio devices' in the control panel.
5.unistall audio driver n reinstall it.
these are basic techniques,but u never know,u might end up listening to music on ur system :-)
god bless.