Update
This is a major change by LM to P3D. They have changed the file structure of the program so that future updates will be able to be done with a patch instead of a complete uninstall/install. You need to uninstall everything P3D before installing v2.5, or you will have problems. There is a lot of info at the P3D page of the AVSIM forum. It looks like you can't save any files by renaming them as the new install finds them anyhow and screws them up. Note that there is also a Hot Fix for v2.5 and it IS just a patch. You do not have to uninstall v2.5 to install the Hotfix. I, for one, am very happy with LM's response and attention to our concerns. FSX, FS9 are dead in the water with no one continuing development of those old programs while P3D is alive and continuing to be developed. I have it running better than any previous Flight Sim program and it continues to get better. All the third party developers are developing addons for it and no one is developing any for FSX or FS9. Just think of it this way: If you were buying a new car, and wanted the best and most reliable one you could get, which would you buy? An old Studebaker with no factory support, service, or parts availability? Or a new Chevrolet or Ford with full factory support, parts and service? Now if you are into Classic cars and are buying a second car to play around with, then of course you can have both. But if you are serious about driving, you would want the real new one.