Changer ma résolution

Bonjour,
J'ai installé linux Ubuntu cet après-midi, mais la résolution est en 800*600.
J'aimerais la changer.
Lorsque je fais Système => Préférences => Résolution de l'écran, seuls 800*600 et 640*480 sont disponibles.
J'ai essayé de télécharger un driver sur Touslesdrivers, mais le plugin pour touslesdrivers.com ne marche pas sur Linux.

Voici mon fichier Xorg.conf (si ca peut servir)


# xorg.conf (X.Org X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the xorg.conf manual page.
# (Type "man xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# Note that some configuration settings that could be done previously
# in this file, now are automatically configured by the server and settings
# here are ignored.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
# sudo dpkg-reconfigure -phigh xserver-xorg

Section "Monitor"
Identifier "Configured Monitor"
EndSection

Section "Screen"
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
DefaultDepth 24
EndSection

Section "Module"
Load "glx"
EndSection

Section "Device"
Identifier "Configured Video Device"
Driver "nvidia"
Option "NoLogo" "True"
EndSection






Merci d'avance