You might try to download the tarball with the kernel driver and untar it. Then, login as root on a text console, stop the X server with "/etc/init.d/gdm stop" for gnome or "/etc/init.d/kdm stop" for KDE, "/etc/init.d/xdm stop" for xdm, ....
Build and install the kernel module by making the extracted NVIDIA_kernel-1.0-4191 directory the current directory and "make install".
Load the module with "insmod nvidia" (you might also need to "insmod agpgart" before the nvidia module), If it works then restart the X11 display manager, i.e. "/etc/init.d/.... start".