There is a windows update that was just released some of you may have already updated I hope things went ok. I recently applied the update on my system at home and the next day I went to go fly a flight when I got the message that the default flight could not be loaded because the aircraft was corrupt. You can imagine my surprise. I closed FSX and proceeded to find out what happened. I discovered that the folder that had the aircraft mentioned had a huge problem the .AIR file was missing as well as the texture folder. Now why this was the only aircraft affected is something I will never know Lucky for me I had the same aircraft on my system at work as I had downloaded there.
Now mind you UPDATES are not supposed to change anything yeah right. So you might want to back anything up before applying the update.
I had no problems when I updated my system at work. So why did it remove files from my system at home is the million dollar question. Answer who knows>