There is a way you can retrieve your Halo CD Key
without digging through your registry.
Belarc Advisor is a free tool that will scan your computer and retrieve many things, including your keys.
It will save an html document on your PC with information such as:
- Operating System
Processor
Drives
Users
Controllers
Bus Adapters
Virus Protection
Communications
USB Storage Use in past 30 Days
System Model
Main Circuit Board
Memory Modules
Display
Other Devices
Network Map
Software Licenses
... and some other things
A big thanks to my friend Anoobis for telling me about this.