Why do i receive no hdmi output from windows 7

[Guest]

Hello,
i just bought a new dell pc, with a HDMI output on the back. ive connected it up to my HDTV but there is no signal. why is this so? and can anybody suggest a solution?

 

[jefe323]

http://www.ehow.com/how_4457043_connect-pc-hdmi-tv.html

 

[Guest]

yeah that dosnt work... i have previously tryed it, and nothing then either. is there another way? do i need to install anything?