It's ATI Radeon and probably gForce2 that supports Hardware Transform and Lighting (Hardware T&L, for short), but this excludes Intel Graphics chips like the 845G graphics chipsets that don't support Hardware T&L.

The really neat features of Hardware Transform and Lighting is that unlike Software Transform and Lighting is that the vertex processing (since a polygon were made up of 3 vertices--no more or less) are done by a video card's Graphics Processor Unit (GPU) and not by a CPU. The other features for which the hardware T&L supports have a support for shaders, materials, etc. What I mean by "material" is let's say that you have a sphere that are "metallic" and that can reflect light.

But since you have an nVidia Riva TNT2 video card, your card only support Software Transform and Lighting. And so the "Software Vertex Processing" are done by your CPU (but the Hardwre T&L that I'm speaking of which the vertex processing were done by the GPU are called "Hardware Vertex Processing"). And so in this case, a "Software Transform and Lighting" were done by the engine like A6, and you won't be able to experience the features which were found in new "Hardware T&L" video cards that support materials but keep in mind: If you buy a new video card like a gForce5 5200 or ATI Radeon 9600, etc., make sure you buy the video card that support shaders like Vertex Shader 2.0 and Pixel Shader 1.4 or higher. Not all Hardware Transform and Lighting video cards support shaders; some video cards might support Vertex Shader 1.1 or 1.2 but not Pixel Shaders.

Hope this helps.