I recently bought a Dell Inspiron with a Nivida Video card and I'm trying to use my Phillips 42 HDTV with little success. I'm using an HDMI to HDMI plug and so far I'm getting jack. My computer doesn't "see" the tv and the TV doesn't show anything on the screen nor does anything happen when I use "duplicate" with the projector program.
I had the same problem you might have to go into the settings of the graphics card and choose what time of setting you want. My old laptop from dell had options for duplicate or side by side. You could try checking different inputs on your tv also as you would have to switch to the hdmi input that your pc was hooked up too. You said that the computer doesnt see the tv and the tv doesn't show but when i hooked my laptop up neither recognized each other you just had to do the setting.