No Sounds in my laptop.......

Hello,
hai
right click "my computer"click "manage"click "device manager"click "sound,video and game controller
open(audio codes,legacy audio driver,legacy video capture device,media control devices,video codes. I can choose any of them it shows this device is working properly.i go to start menu, setting,control panel select sound and audio "it shows "no Audio device" I don't understand whats going on my audio device is working properly.but there is no sound. And my Windows Audio service is started and Startup status is already on "Automatic".
my computeris:-
system
microsoft windows xp
professional
version 2002
service pack 2
computer intel(R)
pentium(R)4
cpu 3.00ghz
1.00 gb of ram
give me the right solution.
thanks