Direct X 9.0 Screws Nvidia

On Nvidia site it says that Direct X 9.0 is not supported. Direct X 8.1 is supported with OpenGl 1.4. I was wondering if anyone knew how to downgrade the direct X.

I am only a novice computer user. Dx 9.0
can not be uninstalled, unless you wipe the
hard drive. Microsoft recommends that you
make sure that system restore is turned on
before installing DX 9.0. That way, if it
does not run well on your system, then you
can restore your computer back to a point
before you installed DX 9.0

I have DX9.0 on my system, and I am using
an Nvidia GeForce 4 ti 4600. At this time
I have run into no problems while playing
various computer games; such as, Unreal
Tournament, Splinter cell (this one recommends Dx 9.0-but 8.1 will do), Unreal2,
and Unreal 2003.
Dx 9.0

I can’t find any reference to DirectX 9 not working on the NVidia site, where is it?

I’m not saying that isn’t the problem, because much evidence suggests that it is, but I’m not seeing it anywhere.