Sound problem Inspiron 700m

Hello,
The sound of my machine is not working one in a while.
It happend very suddenly as it was working fine, but one day there was no sound. After a couple of times restarting, the sound came back. Again it happned for a couple of days and today after 10 time restarting there is no sound. I reinstalled the drivers as well and the hardware based on windows messages is fine.


do you know what else I can do?

thanks
m.