In the past, I always made sure that during program installation, that it doesn't install it to the C:\Program Files, but rather the drive of my own choice. It's a tedious process as you have to keep doing this for every program you install, but in the end it's not so bad.
Yeah, this is the other reason. I'm hoping that a lot of programs installing using the %ProgramFiles% macro. If I change that in the registry then it'd make life just generally easier.
How does Windows react to the "Common" folder being moved?