- last post: 01.01.0001 12:00 AM PDT
Halo PC and Vista are 100% compatible.
In the early days, there was an issue that Vista didn't think it was, however there was a very quick hot-patch to solve this. It was purely an issue of Vista incorrectly reporting that it wasn't.
So your error isn't a generic "Vista" thing, it would be a problem with your hardware/software.