Just before installation finishes installer tries to install PHYSX.
I then receive dialogue stating that current version is newer.

Then when I try to start the game I get the attached message in command prompt.

Please help.

I got curious so I went searching....
You can try what is mentioned here:

http://steamcommunity.com/app/35700/discussions/0/648814845433784102/

But do so at your own risk:-)

It might be related to Adobe Video Exporter. Do you use that?
Regardless, it doesn't appear to have anything to do with PhysX.