I dont think you can. I recall that flight "videos" are not videos in the sense of .avi or .wmv but just the flight data and map coordinates of the flight. Thus the only way to view them is in the sim. You need to download an external video recorder in order to create actual video files.

well, i only know how to do it if you are recording with the stander recorder or fraps, and you have vista.

1. explore your computer
2. click on your acount name
3. click vidios
4. click fsx files or something like that
5. ta da!!!!! your movies should be there