Unable to get audio when connected to HDTV via Displayport/HDMI active adapter

Hi,

I wanted to watch Netflix on my HDTV via my computer so I used an active Displayport HDMI adapter to connect. This is the adapter I'm using:

https://www.visiontek.com/computer-accessories/cables/visiontek-displayport-to-hdmi-adapter-detail.html

The video is fine but the audio comes from the computer not the TV.

The TV doesn't appear under audio playback devices even when I show disabled or disconnected devices so I can't switch it over.

The TV appears as a Generic PnP monitor in Device Manager.

Spec: Dell Optitplex 780 SFF

          Windows 7

          Intel Q45/43

          GMA 4500

          driver 8.15.10.3202

Just thinking that either the integrated video doesn't send HDMI audio over the Displayport, I need a different video driver, or I am using the wrong adapter.

Any help appreciated.

Thanks a bunch!