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)
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).
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.
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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.