... try running the PhysX_9.08.14_9.09.0814_SystemSoftware.exe  in the Binaries/Redist folder.

The files it need should be included in any recent version of your graphics drivers but there is the slimmest of slim chances that the engine might complain. In theory so long as you are running on Windows 7 or later everything the game needs to run should already be part of your operating system.

If you are having any problems then please get in touch with me and I'll try to help you.