Laptop to TV HDMI hookup help?

I'm very tech-savvy but I have been having the hardest time with this. To others, it seem to be plug and go but my issue apparently is too complicated for even the Dell Help Center. My new Dell Inspiron n7110 has a Blu-ray player in it. I want to hook it up to my LG HDTV using an HDMI cable. The TV is on the right input channel, the HDMI is in the right port, but when I hook up the HDMI cable to my laptop, all I can see is my desktop background. No icons and no taskbar. I have tried fiddling with the resolution and the aspect radio. The guy in the Dell Help Center remotely took control of my computer to try to figure it out. I know that I need to have my computer recognize the TV as an external screen but once I plug in the cable, I can't access anything. The TV has yet to register my laptop's output as well. Is it the cable I'm using?