Hey, I found this post, and it works well.
I have a macbook pro 2,2 form 2006
Core 2 Duo
runing win7 in bootcamp 4.0
Followed the directions, and my mouse working great
The answer is to go to http://www.trackpadmagic.com/magic-mouse/home and follow the instructions. IT WORKS! Scrolling and right click with authentic Apple Drivers! That's it! I uninstalled the magic mouse totally before I installed the new drivers. I don't know if you have to. IT WORKS!
PS I think they extracted it from BootCamp.