No sound thru Sony TV with HDMI cable

Hello, I have a Toshiba Satellite laptop & a Sony Bravia TV. When i connect them with a HDMI cable i can only see the picture but sound is still coming out of my laptop. The laptop picture on the TV is far too big, & i can't see the task bar also. How do I can the picture to view all the laptop & how do i get sound through the TV. thanks x