Linux Kernel-Source Package Question

I have a GeForce 3 Ti200 and am running RedHat Linux v9 with the latest
kernel from the RedHat Network update server. (I am not on that machine so
I don't have the version).

I really want to install the latest NVIDIA drivers to get the acceleration
features cooking, but when I get to the installation screen to the point at
which the installer is about to paint my HD with the new drivers, I get this
"No precompiled interface was found to match your kernel".

What is the kernel-source package and where do I find it to install it? I
went to the Add/Remove programs in RH9, but I cannot find anything that
closely resembles this...and yet another Linux mystery.

If anyone can help this newbie, it would be much appreciated.