Tip1: DO NOT install any programs into the default Programs folder of Win 7...especially any programs that you will be modifying, such as your sim. Install your sim to a new folder outside of the Programs folder....even better an a separate HD away from the OS.
Tip2: I copied my installs of FS9 over from my XP system to my Win 7 system and had problems using the flight planning. I was able to get flight planning to work fully once I used the FS Registry repair utility from Flight1, but not all the time....it was hit and miss. So, I did a fresh install of FS9, enhanced it, and moved those planes that I fly most often and for which I actually create flight plans into that fresh install.
As far as the registry files stuff goes...can't help you with that...have never done a hand edit of a registry file before.
OBIO