triple monitor setup

[blizhu]

Hi, I have i7 2600k cpu, z68 motherboard and win7 on my desktop with dual monitors. I don't play games so I don't have a discrete video card on it. Now I want to hook it up to my lcd tv which is nearby, so I can play videos on it for my daughter to watch. What's the best solution for me to do this? Can I just buy a video card, connect the tv to it, and only enable the video card when I play video for my daughter? Thanks in advance.