- DusK
- |
- Noble Legendary Member
Custom Edition is a stand-alone program, meaning you don't "upgrade" your copy of Halo PC.
That being said, Custom Edition is Windows-only. You could try emulating Windows, dual-booting, or tossing your Mac out the window and getting a computer that's not an overpriced pile of proprietary pieces loaded with an OS that most games don't work with.
[Edited on 12.07.2010 2:31 AM PST]