FS2004 needs about 1.8 GB at baseline, but add-ons can raise it to 10–30 GB or 50 GB+. Find out whether 10 GB free is enough.
Microsoft Flight Simulator 2004: A Century of Flight (FS2004 or FS9) officially requires about 1.8 GB of free disk space. For real use, reserve 10–30 GB for a modest add-on collection, or 50 GB and upwards for extensive scenery, aircraft, AI traffic, retained downloads and backups.
FS2004 file size: how much space should I reserve?
A sensible allocation is 3–5 GB for FS2004 itself, 10–30 GB for a typical expanded installation, and at least 50 GB if you intend to collect large scenery packages or complete aircraft fleets.
The 1.8 GB figure in our breakdown of FS2004's original system requirements is Microsoft's baseline free-space requirement. It is not a limit on the simulator folder and does not include a growing add-on collection.
| Installation profile | Typical contents | Space to reserve |
|---|---|---|
| Clean FS2004 | Standard simulator with little or no added content | Official baseline: 1.8 GB; allow 3–5 GB |
| Lightly modified | Several aircraft, repaints and a few airports | 5–10 GB |
| Moderate collection | Aircraft, airport scenery, AI traffic and utilities | 10–30 GB |
| Large collection | Complete aircraft packages, regional scenery, mesh, textures and AI fleets | 50–100 GB or more |
These are planning ranges, not fixed installation sizes. FS2004 has no practical add-on storage ceiling: a heavily expanded installation can exceed 100 GB, particularly when wide-area scenery and old download archives are retained.
I have 10 GB left—is that enough for FS2004?
Ten GB free is enough for FS2004 and a restrained selection of add-ons, but it is tight if this is all the free space remaining on your Windows system drive.
- Usually sufficient: A clean installation, several straightforward aircraft and a few small airport packages, especially when archives are removed or stored elsewhere.
- Likely to become tight: Multiple detailed aircraft, AI fleets, custom sounds and several regional airports.
- Not sufficient for long: Photographic scenery, extensive terrain mesh, large texture packages or a collection in which every ZIP file and backup is retained.
If the 10 GB is on the Windows drive, leave several gigabytes unused for temporary files, updates, paging and archive extraction. An add-on installer can fail with an insufficient-space message even when the FS2004 destination drive has room, because older installers often unpack to the system drive first.
Choose a 10 GB budget only for a deliberately small setup. Choose 20–30 GB for normal expansion, or place large scenery and download archives on another drive.
Which FS2004 add-ons use the most disk space?
Wide-area scenery, terrain mesh and texture sets are usually the largest FS2004 add-ons, followed by complete aircraft and AI fleets.
- Scenery and terrain: A small airport correction may occupy only a few megabytes, while a detailed region or photographic ground package can consume several gigabytes. Scenery can also reside outside the main FS9 directory.
- Aircraft: A basic model with one livery may be small. Packages containing many repaints, virtual cockpits, panels and custom sounds can be hundreds of megabytes or more.
- Textures: Replacement textures accumulate quickly because the active files and the downloaded archive may both remain on disk. As one concrete example, this default-aircraft texture archive is listed at 79.77 MB before considering any retained working copy or backup.
- AI traffic: Flight-plan files are tiny, but the aircraft models and airline liveries behind a complete traffic package are not. Several fleets can add gigabytes.
- Utilities: Weather tools, flight planners and ATC software may install outside
Flight Simulator 9, so they will not appear when measuring only that folder.
Folder size alone does not determine frame rate. Complex aircraft systems, dense AI traffic and detailed scenery may affect loading times and performance, but a large archive folder that FS2004 never reads will not reduce in-simulator frame rates.
Why is the installed size larger than the download?
The advertised download size normally refers to a compressed ZIP or installer, not the extracted files that FS2004 uses.
At the busiest point of an installation, the original archive, temporary extracted files and final installed copy may all exist together. Keep at least two to three times the download size free while installing a substantial package, with a larger margin for highly compressed scenery or texture collections.
After confirming that an add-on works, you can delete its temporary extraction folder or move the original archive to another drive. Do not remove shared files from Gauges, Effects, Sound or common scenery folders simply because the source archive has been moved.
How do I measure the complete FS2004 installation?
The true storage cost is the FS2004 directory plus external scenery, separately installed utilities, archives and backups.
- Measure the main FS9 folder. In File Explorer, open the properties of
Flight Simulator 9and record its size on disk. Common storage locations inside it includeAircraft,Addon Scenery,Gauges,EffectsandSound. Our folder-by-folder FS2004 add-on installation guide explains what belongs in each location. - Check every active scenery path. Review the areas registered in FS2004's Scenery Library and measure any folders located outside the simulator directory.
- Add external programs. Include weather engines, planners, traffic tools and any caches or package folders they maintain.
- Count retained downloads. ZIP files, self-extracting installers, repaint archives and duplicate working folders all use space even though FS2004 does not load them.
- Include backups. Copies of original textures, aircraft and configuration files can quietly become as large as the active content.
For capacity planning, use FS9 folder + external scenery + separate utilities + retained archives and backups. This is more reliable than the size shown for the main simulator folder alone.
Can FS2004 scenery be stored on another drive?
Yes. FS2004 can load scenery from another drive when its folder is registered through the simulator's Scenery Library.
This makes scenery the best content to relocate when storage is limited. Our guide to installing and registering FS2004 scenery folders covers the placement process without forcing everything into Addon Scenery.
Aircraft, gauges, effects and shared sounds are safest in their expected FS9 folders because many legacy installers use the simulator's registered installation path. Avoid dragging the complete Flight Simulator 9 directory to another drive after installation; doing so can break old installers, shortcuts and registry-based path detection.
What do “FS 2004” and “FS9” mean?
FS 2004, FS2004 and FS9 all refer to Microsoft Flight Simulator 2004: A Century of Flight.
The FS9 name comes from the simulator's version and executable naming. The storage figures on this page do not apply to Microsoft Flight Simulator 2020, Microsoft Flight Simulator 2024, FSX or Prepar3D, all of which have different base files and add-on systems.
How much space does installed Prepar3D use?
If your question is “o Prepar3D instalado ocupa quanto?”, do not use FS2004's 1.8 GB requirement: Prepar3D is a different simulator and needs substantially more storage.
There is no honest single figure without the Prepar3D major version and selected components. Plan in tens of gigabytes for the simulator before large add-ons, then include external scenery, add-on packages, installer caches and backups. Check the published storage requirement for your exact Prepar3D version and measure external content separately, just as you would for FS2004.