The title says it all. I've noticed the difficulty of making some games run on the 3Dfx card when you have two video cards, being the other one a capable AGP Nvidia\ATI variant.

For example Carmagedon TDR2000, MidtownMadness among a few others always pick the Nvidia card instead of the 3Dfx voodoo2. Unreal\Unreal Tournament, Monstertruck Madness2 run on the 3Dfx easly (Unreal\UT being able to pick between one or the other). OS seems to play a role in this as when using Win98 i'm given the option in 3dmark 2000\2001 to either use the 3Dfx card or the Nvidia\ATI card. If i'm not mistaken MidtownMadness under Win98 also gives you the same option. Same thing doesn't happen on Windows XP.

Is there a easy way to force a game to use one video acceleration hardware option over the other?