Games (like Half-Life) run D3d and OGL w/ G200 instead of Voodoo2! Help.

[Medster]

My games, like Half-Life, are using my G200 for OpenGL and Direct3d instead of my Voodoo2. I have the newest drivers installed for both the G200 and Voodoo2. If I put the OpenGL on default for 640x480, it'll run the game with the G200 (I can tell cause it's slower and less stable). When I try to run the 3dfx MiniGL driver, it says this video mode is not supported by my video card. I even tried downloading Wicked3d drivers and the old MiniGL driver. Could someone please help? Thanks.