i installed halo one on windows xp sp2 with a qaulifiying video card (geforce mx 4000).  i installed halo and then got all updates needed for the game.  i start the game and the grapics are totally messed up.  when i play the game i cant see other people.  i cant see the gun i am holding or anything like that.  i have never had this problem before.  i am using the latest nvidia drivers as well.

I guess that this is a texture issue.

Check that there aren't any special, workaround, patches for this problem.

Also try using slightly older drivers. I dont mean Detonator ancient, but just a few versions back.