No sound from laptop to tv

Hello,

I tried everything that i read about changing your default to HDMI or Digital output. But still nothing. i even updated my computer and still nothing. I had window vista at first then i change it to windows 7. I don't know maybe that is why its not working. Then i read on your playback list it should show your tv. I right click and clicked on show disabled devices and its still not popping up I don't know whats going on I've been trying for hours now. Please can anyone help!!!