Display Port to HDMI

As in an earlier post I have upgraded my old XP Media PC to a Lenovo M92p running Win7 64 bit. It has a VGA out but also has a mini Display port for which I bought the DSP to HDMI cable.
The PC uses my SONY 46" TV as a screen using the VGA connection no problem but I then need to run audio cables for sound. I bought the HDMI adapter connection but when I plug that in it is not seen by the system. I cannot see the Display Port listed anywhere as a choice of output.
( Amazingly the PC has listed the SONY TV as the display over the VGA cable. Don't know how it knew that )

You can not use an adapter for VGA/DVI to HDMI and expect to get sound. There is no sound signal coming from the VGA or DVI ports...hence the need for audio cables as you found out. To receive sound from an HDMI cable you have to connect the HDMI cable to HDMI ports on both ends of the cable. You can use a(n) HDMI mini port adapter to go from full size to mini size.

The Adapter is in the Mini Display Port, not the VGA adapter. Ok so maybe sound is not available through the Display Port but I cannot get the Display Port connected through the HDMI adapter to the TV.