My system is :
NF7S 2.0
Barton 2500
Audigy sound card
2x256 pc2700 crucial ram
60gig barracuda IV hard drive
Win98se
latest Omega drivers

When I first started playeng Halo, the game was running fine but without any
colour textures just the various 3d models. Eventually sorted it by going to
the D3D settings in 3D section of the advanced section for display settings.
Moving the settings from performance, to Balanced got everything running as
it should be. Running at 800x600 instead of 1024x768 as it is beyond my
system. Have not put in either of the patches yet, havent found any need for
them, game is stable and apart from occasional slow down when it gets hectic
game runs fine. Will maybe experiment later, and probably foul it all up.
One final thing have added -use11 to the halo.exe so that it reads
halo -use11.exe when highlighted.