Whenever I turn on my laptop at the bottom right hand corner of the screen where the volume level is usually displayed is a small red circle with a white cross in it and when I hover the cursor over it I am informed that no audio output device is installed. When I restart my laptop it sometimes goes away and I am able to watch/listen to things with sound but more often than not I am informed that no audio output device is installed. I would like to know how to fix this. It has been going on for about a week now and I am not sure why it started. I have browsed the internet for solutions but everything I have tried has failed to solve the problem.
Please help! Laptop is a sony vaio VGN-N38Z/W