Display port on E6400

I can't seem to get the display port on my e6400 to work. I don't notice a discrete entry in the hardware manager,  Does anyone know if the display port is supported when using windows XP pro?

I wanted to hold off upgrading to windows 7 but I may have to if the display port does not work.

I have a display to HDMI adapter and from there I plugged the HDMI cable into the HDMI port on my TV.  THe TV does not detect the port and the the Laptop does not detect the TV even though I have tried to set the laptop to the Display port and the TV to the HDMI port.

Thanks
John