no 3D (nvidia)

i have installed nvidia drivers.when i try run Nvidia x server settings,there is note:
“You do not appear to be using the NVIDIA X driver. Please edit your X configuration file (just run nvidia-xconfig as root), and restart the X server.”
and then i do that stuff,but i try run again Nvidia x server settings there is the same note.
What can i do?
Restart x server,how to???

I’ll just explain it in the simplest way such that YOU can understand it.

First logout and then login as a root user. (Type ‘root’ in the Name box and then the admin password which you first gave.)

Then open the Konsole and type nvidia-xconfig.

Finally restart the system.