Good info, and here is another way
from KDE desktop
open system > Adept
search for 'nvidia'
From the results, expand 'nvidia-glx', note the guidance in the visible text
install the driver
end your current session
on the log-in screen, restart the 'X-Server'
on the next log-in screen, log in.
finally, open the system Settings > monitor & Display and configure your 'hardware'.
You may have to restart your X-Server