I have had trouble on my Toshiba A75-s206 with losing all sound. There is no sound with tunring on the laptop as Windows open, nor is there sound when I try to listen to music, watch a DVD, etc. When I go to my control panel and open the sounds and audio devices, the Device Volume area is greyed out so that nothing can be changed. i have had this problem intermittently. every once in a while when i restart it, the sound will return, and then it is gone again. Any help would be appreciated. thanks.