Which operating system are you running? Windows xp? Windows 7? Windows 8? Mac OS?
If windows right click a blank spot on the desktop and choose "Screen Resolution" if you want to have 2 seperate areas (video on one screen, and a desktop on the other) you will choose "extend my desktop" and then you will need to drag the browser that is watching the video over to the "tv" monitor area.
As for the sound, in your control panel select "sound" and you should see the HDMI there as digital audio, right click it and set it as the default device... you might need to close and re-open the browser that is watching sunday ticket for the sound to start up.
If indeed you are using windows you might have better luck in the microsoft forum here »Microsoft