If you have an Nvidia card:
Goto Nvidia control panel while you have your computer hooked up to your TV then go here:
http://gyazo.com/2fdd0ef6614d3df0c5b8786d9d430bbe
http://gyazo.com/9448373e957e156f1daaea542505befe <--- check the box
And no, this will NOT AFFECT other display sources...