Hardware Transform & Lighting.
This is basically the defacto of using a modern GPU to shade polygons (the prime function of a modern GPU). I think just about any 3D video board since GeForce 256 will support this feature... So chances are you indeed have it.
AMD X2 4400+ Toledo 1MB/Asus A8N-SLI Deluxe/2GB Kingston HyperX/SLI Gigabyte 7800 GTX 256MB/Creative SB Audigy 2 ZS Plat w/ Creative Inspire 6.1 speakers /180GB Hitachi PATA/19\" AG Neovo F-419 LCD/OCZ PowerStream 600W PSU/WinXP Home SP2