The FSXDemo.exe file you have requested: Official Demos / Flight Simulator X - Final Demo - 798.28mb is not available. Perhaps try browsing all files for the game Flight Simulator X and upload any files you want to share or are missing. This is the only information we could locate:
Microsoft has released the final demo, allowing you to check out two airports, two missions, and three different aircraft. All of the missions take place at St. Maarten in the Caribbean.