Never use GeForce experience to 'optimize' crap. It's terrible and doesn't know what the hell it's doing. With your system, its easy: just max out everything.
Hell, GeForce experience even breaks my Skyrim just by being
installed.
I'd recommend removing it completely and getting the new drivers from
http://www.geforce.com/drivers
Learning how to configure your game's graphics by yourself will help for future games you can't safely max out. I mean, you
should already know how to do that considering you're trying to set up a post-process injector.