Original Halo:Combat Evolved on Vista (with an 8800GTS 512MB Video Card)-please respond!

Original Halo:Combat Evolved on Vista (with an 8800GTS 512MB Video Card) -
That is the senerio. What I get is severe lag, and frame rates that start
at 300+ and end up at 10, where the game is unplayable. I have heard the
8-series cards don't get along with some games, and Vista makes it even
worse. My problem with that is, how long has Vista been out to the public,
and that there is now Vista, with SP1, and how long has nVidia been
releasing drivers. A solution should have been found. Bungie, Halo's
creator doesn't reply to this, maybe they are happy with the fact that those
with XP only play Halo:CE and with Vista Halo2 (BTW, I do have that-there's
NOT ENOUGH MAPS AND PLAYERS, THOUGH). The greed of business.

Microsoft does not have an answer, they suggested, during over 1 hour of
service, going into msconfig and using "selective services", basically
shutting off everything but the game, and this is supposed to fix the
problem. It did not. I am at a loss, I am conservatively knowledgeable
when it comes to computers, but, can't find a fix for this. Any help is
appreciated.

Thank you.