System Specifications (To the Best of my knowledge):
10+ year old computer.
Pentium II (800-900 MHz) Processor
128 MB of RAM
nVidia SGS Thomson (Joint Venture) RIVA128 Graphics Card (rev 10)
GNOME
Ubuntu 8.04 Hardy Heron
Driver in use: nv (I would like to know how to disable this. nv does not show up in the "hardware drivers" interface)

I think that sets the scene here. So I am trying to install a more tuned nVidia driver (The latest Legacy) onto this aging computer, and it gives me an error (wahh nothing works on the first time :P) :
ERROR: Unable to load the kernel module 'nvidia.ko'. This happens most frequently when this kernel module was built against the wrong or improperly configured kernel sources, with a version of gcc that differs from the one used to build the target kernel, or if a driver such as rivafb/nvidiafb is present and prevents the NVIDIA kernel module from obtaining ownership of the NVIDIA graphics device(s).
[[Extra]]
Please see the log entries 'Kernel module load error' and 'Kernel messages' at the end of the file '/var/log/nvidia-installer.log' for more information.
[[Next page]]
ERROR: Installation has failed. Please see the file '/var/log/nvidia-installer.og' for details. You may find suggestions on fixing installation problems in the README available on the Linux driver download page at Welcome to NVIDIA - World Leader in Visual Computing Technologies.

Any help would be greatly appreciated.