Back again. I would try to uninstall the “NVIDIA PhysX v8.09.04” via Control Panel (but not the “NVIDIA Drivers”), and then re-install it again. The PhysX System Software alone can be downloaded from from the NVIDIA page above. If this doesn’t help try to use an older PhysX System Software version, for example v8.04.25. I have heard rumors that the combined installer has some problems.
But before you do please download the following dll and replace it with your version. It adds a few debug outputs at the time of engine initialization. Then run this small script and post the console output:
http://enn0x.p3dp.com/libpandaphysx.pyd
from pandac.PandaModules import loadPrcFileData
loadPrcFileData( '', 'notify-level-physx spam' )
#import direct.directbase.DirectStart
print '--pre--'
from libpandaphysx import PhysEngine
print '--post--'enn0x