How do I install add-ons in Microsoft FS2004?

To install add-ons in Microsoft Flight Simulator 2004 (FS2004/FS9), extract the download to a temporary folder, read its instructions, then copy each component into the matching FS9 folder—usually Aircraft, Addon Scenery, Gauges or Effects. Scenery must also be activated in the Scenery Library; aircraft normally appear automatically.

Find the correct Flight Simulator 2004 folder

The FS2004 root folder is the directory containing fs9.exe. Common locations include C:\Program Files\Microsoft Games\Flight Simulator 9 and C:\Program Files (x86)\Microsoft Games\Flight Simulator 9, but a custom installation may be elsewhere.

Do not rely on a downloaded installer's suggested path. Browse to the actual folder containing fs9.exe. On protected Windows folders, approve the file-copy permission and then verify that the files reached FS2004 rather than a virtualised user folder.

How should I prepare an FS2004 add-on?

1. Extract the archive elsewhere. Use a temporary folder rather than opening the archive and dragging files straight into FS2004. This makes nested folders and documentation easier to inspect.
2. Read the included instructions. The package may require a specific base aircraft, extra gauges, scenery-library activation or files in several destinations.
3. Identify the package type. A complete aircraft, repaint, scenery package and panel upgrade all use different folder layouts.
4. Back up files before replacing them. Never approve every overwrite without checking what the add-on changes.
5. Install one package at a time. Start FS2004 and test it before adding the next one, so faults are easy to trace.

For archive handling and recognising complete aircraft versus repaints, see our practical guide to extracting and placing simulator downloads.

Which FS2004 folder does each add-on use?

These are normal destinations, not permission to scatter every file by extension. Preserve the package's supplied structure and follow its readme when it specifies a different location.

How do I install aircraft in FS2004?

A complete FS2004 aircraft belongs directly inside the simulator's Aircraft folder.

1. Locate the aircraft's main folder. It should contain aircraft.cfg, an AIR file and usually model, panel, sound and one or more texture folders.
2. Copy that complete folder into Flight Simulator 9\Aircraft.
3. Install supporting files supplied in folders such as Gauges or Effects, merging them with the matching FS2004 folders without deleting existing contents.
4. Start FS2004 and check the aircraft-selection screen. Look under the manufacturer and model names defined by the package, not necessarily its download name.

The mistake we see constantly is an extra folder level. The correct arrangement is Aircraft\PackageName\aircraft.cfg, not Aircraft\PackageName\AnotherFolder\aircraft.cfg. If the extracted archive contains a top-level Flight Simulator 9 or Aircraft folder, copy its contents into the corresponding existing folders rather than keeping that wrapper.

What if the download is only a repaint?

A repaint is not a complete aircraft and will not work without the exact base model it was designed for. Install the required aircraft first, copy the new texture folder into it, then add the supplied [fltsim.x] entry to that aircraft's aircraft.cfg.

Renumber the entry so the sections form an unbroken sequence such as [fltsim.0], [fltsim.1] and [fltsim.2]. Preserve the original configuration file before editing it, and do not substitute a similarly named model unless the repaint documentation says it is compatible.

How do I install scenery in FS2004?

FS2004 scenery should normally have its own folder containing a scenery subfolder and, where needed, a texture subfolder.

1. Create or copy the package folder under Addon Scenery.
2. Open FS2004's Scenery Library from the simulator settings and choose the option to add an area.
3. Select the package folder that directly contains the scenery and texture subfolders—not the scenery subfolder itself.
4. Confirm the area is enabled and place it at the priority recommended by its documentation.
5. Allow FS2004 to rebuild its scenery indexes, restarting the simulator if requested.

Keeping each package separate makes priority changes and removal far safer than dropping every BGL file into the shared default folder. Our FS2004 scenery installation walkthrough covers folder structure, library activation and layer priority in more detail.

How are gauges, effects and other support files installed?

Global FS2004 gauges normally go in Gauges, while visual-effect files go in Effects. Copy any accompanying textures or sounds only to the locations named in the package instructions.

Leave gauge CAB files compressed unless the documentation specifically says to unpack them. Some XML gauges and panel components must retain their internal folder names, while aircraft-specific gauges may be supplied inside the aircraft's panel folder. A worked FS2004 gauge-package example shows how one add-on divides files between the common FS9 folders.

Be more cautious with DLL files placed in Modules. They must be intended for FS2004 and may depend on other software. Do not install an unknown executable or disable security software merely to make an old package run.

Why does the FS2004 add-on not appear?

Most missing add-ons are caused by an incorrect folder level, an uninstalled dependency or scenery that has not been activated.

• Aircraft is absent: confirm that aircraft.cfg sits directly inside one folder under Aircraft. Check that the package is a full aircraft rather than a repaint.
• Repaint is absent: verify the required base model, the texture-folder name and the corresponding texture= value. Check for skipped or duplicated [fltsim.x] numbers and duplicate title= values.
• Scenery is absent: make sure the area is enabled and that the library points to the folder containing the scenery subfolder. Check its layer priority if another airport occupies the same location.
• Panel is black or incomplete: install every supplied gauge and confirm that required third-party gauges are present. Gauges made only for another simulator may not work in FS2004.
• Effects are missing: check that the package's FX files and any associated textures reached the correct Effects locations.
• Files seem to copy but nothing changes: Windows may have blocked or redirected writes under Program Files. Inspect the real FS2004 folders after copying.
• FS2004 crashes after installation: remove the latest add-on and restore overwritten files. Incompatible models, gauges and modules are common causes.

FSX, Prepar3D and modern Microsoft Flight Simulator packages are not drop-in replacements for FS2004 add-ons. Use files explicitly marked for FS2004 or FS9 unless the author provides separate compatibility instructions.

Can I use an automatic installer?

An automatic installer is suitable only when it explicitly supports FS2004 and lets you confirm the folder containing fs9.exe. Older installers often assume a default location, so check their destination before proceeding and inspect the simulator folders afterwards.

If an archive can be installed manually, we generally prefer that method because every copied or replaced file remains visible. Keep the original archive and a simple record of installed folders; if you later need to undo the changes, follow our safe FS2004 add-on removal procedure rather than deleting shared gauges or effects indiscriminately.