After a kernel upgrade Nvidia driver decided to stop functioning caused the X window system crashed.
Kernel upgrade >> Nvidia driver stop functioning >> manuall nvidia driver installation >> this error:
ERROR: Unable to determine the version of the kernel sources located in '/lib/modules/2.6.35-30-generic/build'. Please make sure you have installed the kernel source files for your kernel and that they are properly configured; on Red Hat Linux systems, for example, be sure you have the 'kernel-source' or 'kernel-devel' RPM installed. If you know the correct kernel source files are installed, you may specify the kernel source path with the '--kernel-source-path' command line option. ERROR: Installation has failed. Please see the file '/var/log/nvidia-installer.log' for details. You may find suggestions on fixing installation problems in the README available on the Linux driver download page at www.nvidia.com.
//remove existing driver $ sudo apt-get remove nvidia-XXX nvidia-settings nvidia-current // install nvidia-glx 173, other nvidia-glx-XXX will not work with Go7400!! $ sudo apt-get install nvidia-glx-173 // create xorg.conf $ sudo nvidia-xconfig // might want to reboot to prompt before doing this $ sudo reboot // and X revived!