ViewSonic VX2250wm-LED drivers will help to eliminate failures and correct errors in your device's operation. Download ViewSonic VX2250wm-LED drivers for different OS Windows versions (32 and 64 bit). After you have downloaded the archive with ViewSonic VX2250wm-LED driver, unpack the file in any folder and run it.
I followed the instructions in this thread, particularly the last entries regarding the 50-monitor.conf file.
I have not uninstalled the NVIDIA drivers because I believe that the currently installed drivers are the ones from the 11.4 repository.