I recommend you don't install any 3rd party NV tools at the moment
These can cause more problems especially if there's a driver fault.
Post your IL2 1946 v409m conf. file contents here please .
Meanwhile download the latest NV driver and also Driver Sweeper
http://www.guru3d.com/category/driversweeper/
Use as per instructions and clean the driver up.
Install latest or preferred driver, then pop back here