I am using windows xp. My pc sound was ok but now no sound if i go 'volume control' it shows no audio mixer devices installed. In 'device manager' under 'sounds, video & sound controllers' in 'Realtek high definition audio' shows yellow mark. I already uninstalled and re installed the device but no sound yet. Also i installed motherboard cd for Realtek HD audio again then it shows installed but not working properly (code10) , yellow mark remains. Pls help me.