I tried removing it manually, removing keys because it constantly told me i already had a newer version installed etc, but here's the final solution: You probably have a PhysX System Software installed, because that's what we deal with nowadays.
This stuff might look cody and complicated but it's really as simple as it can get, don't worry Took me ages to find a fix, but i finally found a really easy one.
You could be wondering what the ♥♥♥♥ that is, but more importantly you should wonder how to fix it. So many people get an error that their AGEIA physx thing could not 'init'.