Congratulations, glad we could help.
As for those stubborn old files, they shouldn't pose a problem as long as you follow that guide every time you update your video drivers. A quick note on video drivers, if they aren't broken, don't fix them; that is, just because there is a newer driver doesn't mean you should update unless:
A) You are experiencing a problem with a game or application and would like to see if new drivers will fix that problem.
B) The new drivers offer a feature not available with your current drivers.
Updating video drivers when they are working for you could cause some programs that worked before to break.
Good luck with the 4th monitor and come back anytime.