How do I connect my Latop (playing Windows 7) to my HDMI Tv?

I used to connect and just change my volume when i had vista. But now that the same computer is 7 i can't get the volume working. I have a hp pavilion. And my TV is a plasma philips 32 inch. I want to connect with an HDMI cord like i used to. Is windows 7 not capable of that?