Can I install FSX and Microsoft Flight Simulator on the same PC?
Install FSX alongside Microsoft Flight Simulator 2020 or 2024 safely, with clear advice on folders, add-ons, disk space and common conflicts.
Yes. Microsoft Flight Simulator X, boxed or Steam Edition, can be installed on the same Windows PC as Microsoft Flight Simulator 2020 or 2024. They use separate program, configuration and content folders. The main constraints are disk space, add-on installers choosing the wrong simulator, and keeping each simulator’s files separate.
Which Flight Simulator versions can coexist?
FSX, FSX: Steam Edition, Microsoft Flight Simulator 2020 and Microsoft Flight Simulator 2024 are separate applications and can coexist on one PC. They may be installed on the same drive or on different drives, provided each has its own folder.
| Simulator | Typical file arrangement | Main concern |
|---|---|---|
| Boxed FSX | Its own Microsoft Flight Simulator X program folder | Older add-on installers and protected Windows folders |
| FSX: Steam Edition | Steam\steamapps\common\FSX inside the selected Steam library | Legacy installers may look for boxed FSX instead |
| MSFS 2020 or 2024 | Application files plus separate packages and content folders | Finding the correct Community or package location |
Installing both boxed FSX and FSX: Steam Edition alongside modern MSFS is also possible, but those two FSX releases are more likely to confuse legacy installers. Our explanation of the registry and add-on differences between boxed FSX and Steam Edition covers that more complicated arrangement.
How should I install FSX and Microsoft Flight Simulator together?
Install each simulator normally, give it a distinct location and launch it once before adding modifications.
- Choose separate folders. Never install FSX inside an MSFS Packages or Community folder, and do not place modern MSFS content inside the FSX directory.
- Check available storage. Allow room for each simulator’s base files, updates, scenery, aircraft and caches. Neither simulator reuses the other’s scenery data.
- Install and launch each simulator once. This creates its configuration files and lets add-on tools detect the installation properly. Installation order does not matter.
- Identify the modern MSFS content location. It varies with the Steam, Microsoft Store or Xbox app installation and any custom folder selected during setup. Use our guide to locating the modern simulator’s Packages and Community folders rather than guessing.
- Check every add-on installer’s destination. A mistake we see constantly is accepting an automatically detected path without confirming which simulator it belongs to.
If starting with a clean installation, placing legacy FSX in a custom folder or Steam library outside protected Windows directories can make manual add-on management easier. This is a convenience rather than a requirement for running both simulators.
Will FSX add-ons work in MSFS 2020 or 2024?
No. FSX aircraft, gauges, scenery and missions are not directly compatible with Microsoft Flight Simulator 2020 or 2024, even when both simulators are installed on the same computer.
FSX add-ons belong under the FSX installation and use FSX-specific configuration files. Modern MSFS add-ons normally use its Community folder or managed content system. If an FSX installer asks for a simulator root, our FSX aircraft folder and installation checks show how to confirm the correct destination.
Some external utilities support several simulators, but they still require the appropriate version or a separate profile for each one. Do not copy an FSX DLL, gauge or aircraft folder into modern MSFS and expect it to load.
Can FSX and MSFS run at the same time?
Windows may allow both simulators to launch, but running them simultaneously is impractical. They compete for processor time, graphics memory, system memory, audio devices and flight controls, while companion utilities may attach to the wrong simulator.
Close one simulator before opening the other. Controller assignments, graphics settings, saved flights and logbooks remain separate, so calibrating a joystick in FSX does not configure it in MSFS 2020 or 2024.
What problems can a side-by-side installation cause?
Most problems come from incorrect paths or insufficient storage rather than a direct conflict between the simulators.
- Add-on installed into the wrong FSX edition: Re-run the installer and select the actual boxed or Steam FSX root folder.
- Modern add-on missing from MSFS: Confirm that it is in the active Community folder; multiple old or unused Community folders may exist after moving content.
- Access denied errors: Do not take ownership of protected application folders simply to install an add-on. Use the simulator’s supported content location or a suitable custom FSX library.
- Unexpected disk usage: Check both simulators’ scenery, package and cache locations. Installing them on one PC does not deduplicate world data.
- Utility connects to the wrong simulator: Close the unused simulator and select the correct profile or executable in the utility.
Uninstalling FSX does not normally remove modern Microsoft Flight Simulator, or vice versa. Shared external utilities may need to be repaired or reconfigured afterwards, so keep add-ons and support tools clearly labelled by simulator.