Doesn't matter if you have an ATI or Nvidia hardware. It just needs the PhysX driver to be installed. Check in Control Panel if you have one already installed out there. If it is, then un-install it and download the latest version from here: NVIDIA DRIVERS 9.09.0814
It has nothing to do with the Catalyst Control Centre. It's just a stand alone PhysX driver which certain PhysX supporting games need to be installed. Rest assured, nothing will happen to your existing hardware (or even software for that matter).