Did you delete the shader files? I usually delete them with every new driver install and also reset my NI settings.
Folder:
P3Dv3:
"C:\Users\<YourUserName>\AppData\Local\Lockheed Martin\Prepar3D v3\Shaders\"
FSX:
"C:\Users\<YourUserName>\AppData\Local\Microsoft\FSX\Shaders"
"C:\Users\<YourUserName>\AppData\Local\Microsoft\FSX\Shaders10"