Symptom: 
You start Halo Custom Edition (CE) and it loads normally, you see the Halo animation hear the music but cannot see the menu items.  Clicking around you can hear the menu activation beep/sound.

Cause:
Most new video drivers especially those for Vista now have the anti-aliasing set to ON as default.  You need to turn off or set to application controlled the anti-aliasing setting in your video driver. Be sure you set it for the haloce.exe program and not just Halo (halo.exe). The Halo Custom Edition (CE) game has different video routines that use “fast shaders” to improve the visuals and those routines do not operate with anti-aliasing set to on in the video driver. The Halo PC retail version does not utilize the enhance graphic routines. That is why Halo PC works with anti-aliasing when Halo CE doesn't.