I was having issues with Halo running on my machine:
Windows xp fully updated
P4 2.8mhz
1GB DDR
120GBSATA
9800AIW Pro
I have the Catalyst 3.9 drivers installed and it would crash during certain cinematic scenes. Well I tried this guys solution and it worked for me

so here it is:
VI. Video Issues
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Halo Crashing at startup?
Direct3D Error?
RUN DXDIAG?
I ran into these problems with my ATI Radeon 9000 Pro
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Go into your direct3D settings for your video card
Make your settings identical to mine
WARNING: Make sure you are in DIRECT3D - NOT OPENGL
-Vsync is turned to "Application Preference"
-Smooth Vision Off
-Truform Off
Right click on Halo icon/shortcut and under "Compatibilty"
change the running mode from Windows XP to Windows 98
(if you are using windows xp - it should say Windows 98/ME)
Run halo
- if you still run into problems try using my command line
"C:\Program Files\Microsoft Games\Halo\halo.exe" -console -useff -novideo -vidmode vidmode 1024,768,100
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