Connecting Dell Studio Desktop with HDMI to LCD TV with HDMI

Hi, i am trying to connecting my brand new dell studio desktop conputer with an HDMI hook up in the back to my 32 inch samsung TV with an HDMI connection. I connected both with an HDMI cord, but when i go to the input on my TV nothing shows up on the screen. Is there something i should do in the TV menu, and is there something i should download on my computer to make it work, and or do something with the screen resolution? I should also note that when i connected my DVI to HDMI with the tv and computer my PC showed up on the TV but the cord is too short to use on the tv and i had an HDMI cord laying around and i would rather use that. Do you think the HDMI connection on my new PC doesnt work, or does it have something to do with some tweeking on the computer or a download.

Thanks