It depends on which type of laptop you have but there should be a button on the top, doubling as a function button (on mine it is F10); you use this to scroll thru the options of having a single, double, extended etc screen.
Well done on having a TV with good speakers, you can always plug in spare speakers to the headphone socket on the laptop too (or of your Ipod/ audio player)
If you don't have an F10, look up the manual online for how to connect the HDMI for your model
I have a pastry shop and i wanted to get some nice music going during the afternoon. Since i dont have a sound system i have to work with my laptop and my Tv to get that going. I tried and it works perfectly, but i dont want the tv showing what im doing on the laptop what can i do?