Find the FSX installation folder on Windows for boxed and Steam editions, with default paths, custom library steps and checks for the correct folder.
On 64-bit Windows, boxed FSX normally installs in C:\Program Files (x86)\Microsoft Games\Microsoft Flight Simulator X. FSX: Steam Edition normally sits in C:\Program Files (x86)\Steam\steamapps\common\FSX, or the equivalent path in a custom Steam library. The correct installation folder contains fsx.exe alongside folders such as SimObjects, Gauges and Addon Scenery.
What are the default FSX installation paths?
The default path depends on your FSX edition, Windows architecture and whether you chose a custom location during installation.
| FSX edition | Typical installation folder |
|---|---|
| Boxed FSX on 64-bit Windows | C:\Program Files (x86)\Microsoft Games\Microsoft Flight Simulator X\ |
| Boxed FSX on 32-bit Windows | C:\Program Files\Microsoft Games\Microsoft Flight Simulator X\ |
| FSX: Steam Edition in the default 64-bit Steam library | C:\Program Files (x86)\Steam\steamapps\common\FSX\ |
| FSX: Steam Edition in a custom library | D:\SteamLibrary\steamapps\common\FSX\, with the drive and library name varying |
Seeing boxed FSX under Program Files (x86) is normal. FSX is a 32-bit application, even when Windows itself is 64-bit.
How do I find the exact FSX folder?
Steam's local-files command is the most reliable method for Steam Edition; boxed FSX can be located from its shortcut or running process.
- For FSX: Steam Edition: open the Steam Library, open the game's Properties and use the installed-files option to browse local files. Steam opens the folder containing
fsx.exe. - For boxed FSX: right-click the FSX shortcut, select Properties and inspect the Target field. The directory before
\fsx.exeis the installation root. - If FSX is running: open Windows Task Manager, find
fsx.exeunder Details, right-click it and choose Open file location. - As a fallback: search your drives for
fsx.exe. If several copies appear, choose the one surrounded by the normal FSX folders and confirm it is the executable used by your shortcut.
How can I confirm that it is the correct folder?
The genuine FSX installation root is the directory that directly contains fsx.exe.
- It should also contain folders such as
Addon Scenery,Effects,Gauges,Missions,SimObjectsandSound. - Do not select the parent
Microsoft Games,commonorSteamLibraryfolder when an installer asks for the FSX directory. - Do not select
SimObjects\Airplanesunless the installer specifically asks for the aircraft folder rather than the FSX root.
The similarly named folder under %APPDATA%\Microsoft\FSX stores per-user settings such as fsx.cfg; it is not the installation folder. Depending on installation history, Steam Edition may use a profile folder named FSX or FSX-SE. The Flight Simulator X Files folder under Documents contains saved flights and related user files, not the simulator executable.
What if an add-on installer cannot detect FSX?
If you can locate and run fsx.exe but an installer still reports that FSX is missing, the likely problem is an absent or incorrect registry path rather than the installation folder itself.
First browse manually to the directory containing fsx.exe. If the installer offers no manual browse option or rejects the correct folder, follow our procedure for checking and repairing FSX's Windows registry entries. Boxed FSX and Steam Edition use different registry information, so avoid creating guessed entries.
Should add-ons be copied into the FSX root folder?
Usually not: the installation root is a reference point, while each type of add-on has its own destination and folder structure.
Aircraft normally go below SimObjects\Airplanes, but a complete package may also include gauges, effects or sounds. Our FSX aircraft installation instructions explain how to preserve that structure. Mission packages use another layout, covered in our steps for installing FSX missions.
Because the standard FSX locations are under Program Files, Windows may request administrator permission when files are changed. Some old installers can also redirect files into %LOCALAPPDATA%\VirtualStore; that location is not the real FSX root.