Sound problem

Hello,
right click "my computer" click"manage" click "device manager" click "sound, video & game controller open (audio codes, legancy audio drivers, legancy video capture device, media control devices, video codes. ichoose every of them it shows "This device is working properly" then i go to start menu , setting , control pannel slect "sound & audio" it shows no sound device dont understand what is going on my video device is working properly but there is no sound.
my computer is
system
microsoft windows xp
version 2002
service pack 2v 2096