Ik neem aan dat Ubuntu geïnstalleerd is, als het Grub menu verschijnt, kies de tweede optie, recovery mode, als alle regels voorbij zijn kies in het menu fix xserver. Doorloop de stappen en start de PC opnieuw op. Schakel ook van te voren in de BIOS de onboard video kaart uit. Ik heb zelf ook de 7600 kaart hierbij mijn xorg.conf misschien heb je er iets aan.
gijs@gijs-810:~$ sudo gedit /etc/X11/xorg.conf
[sudo] password for gijs:
# 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
Option "DynamicTwinView" "FALSE"
EndSection
Section "Module"
Load "glx"
EndSection
Section "Device"
Identifier "Configured Video Device"
Driver "nvidia"
Option "NoLogo" "True"
EndSection