Re: 560 can't do physx?
Yes, you can use the clean install option to do a sort of roll back. If remnants of older drivers are present it can cause problems and conflicts.
I'm not really sure what those audio drivers are, I'm an audiophile and I compose music on my rig with various Daw's So i was really surprised i all of a sudden had a new "audio card"
However it is a device that can not be selected. So i think its only a sound reroute when using the Hdmi connector.
You could always disable the Nvidia High def entries in the Device Manager and then uninstall the drivers so they won't appear again.