Help with Sound

Hello,

I have a Toshiba Laptop, Windows 7. I have purchased a HDMI Cable to hook from the laptop to tv for sound. I have video on the tv although sound is only on the laptop. I have tried the troubleshooting of going to control panel, selecting sounds and right clicking on the hdmi. However, when I do so, it does not allow me to click the set as default.
Can someone please assist me so I may get sound to the tv?

Thank you in advance!