I am running Windows 7, and I have orbiter installations all over the place. None of them are in "Program Files" though.
I did edit the Orbiter.cfg file by adding the line:
I saved it, went into Orbiter, and the map mode had indeed changed back to the original version (for 2006), but when I exited out and tried to go back into the Orbiter.cfg, the line that I put in had disappeared!
Hmm, now that I am trying to recall, I can't remember if the Launchpad was open or not. I imagine I would have closed it before messing with the config. But at any rate, it was really weird to see that line just disappear, and adding that line again and setting the value to 1 doesn't help either...I ended up deleting that install yesterday because there were a bunch of add-ons that were slowing down my computer anyway, so it's really not a big deal...
Just tried it again, and same thing. The line disappears from the config file and setting the value to 1 does not revert it back. (The launchpad was closed when I edited the CFG.) I guess the easiest solution is to simply use the new Map MFD (which is better anyways) from the start.