If you want only use your tv, you should be able to simply unplug you monitor and your pc should recognize and use the tv (I would turn on the pc before you unplug anything.)
Or you can go...
Control Panel\Appearance and Personalization\Display\Screen Resolution
you should see 2 monitors, choose only to use the tv in the drop down menu
I tried the first one , but i dont see anything on my TV screen. As for the second one, it just shows me the computer monitor(dell monitor) and not the other option =/