After i did all this on the instructions, i'm trying to install Linux Display Driver Version 96.43.23 and get the message:

ERROR: The kernel header file
'/lib/modules/3.7-trunk-686-pae/build/include/linux/version.h' does not
exist. The most likely reason for this is that the kernel source files
in '/lib/modules/3.7-trunk-686-pae/build' have not been configured.

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

how can I fix it?