Fix the FSX requires XP SP2 error on Windows 10 or 11 by clearing incorrect compatibility settings from setup.exe, autorun.exe or fsx.exe.
The “Flight Simulator X requires Windows XP Service Pack 2” error in boxed FSX or FSX: Steam Edition on Windows 10 or 11 is normally caused by an incorrect compatibility-mode setting. Clear compatibility mode for the affected setup.exe, autorun.exe or fsx.exe, including its all-users setting, then run it again. Do not install XP SP2.
Why does FSX ask for XP SP2 on Windows 10 or 11?
FSX asks for XP SP2 because a Windows compatibility layer is making its old version check see an earlier operating system. This often follows an automatic compatibility recommendation or an outdated installation guide that tells users to force Windows XP mode.
The original boxed FSX required Windows XP Service Pack 2 or later. Windows 10 and 11 already exceed that operating-system requirement; an XP service pack cannot and should not be installed on them. Our explanation of the original FSX requirements and edition differences puts that old specification in context.
How to fix this problem on Windows 10 or 11
To fix this problem, remove the legacy Windows compatibility setting from the executable that produces the warning.
- Close FSX and its installer. Steam Edition users should also stop the simulator before changing
fsx.exe. - Locate the affected executable. For a boxed installation, open Disc 1 and find
setup.exe. If the warning appears when FSX starts, find the installedfsx.exe. Steam users can use Steam’s browse-local-files command to reach the actual installation folder. - Open its compatibility properties. Right-click the executable, select Properties, then open the Compatibility tab. Check the executable itself rather than relying only on a desktop shortcut.
- Disable compatibility mode. Untick Run this program in compatibility mode for. Do not select Windows XP SP2 as a workaround on a modern version of Windows.
- Check the all-users setting. Select Change settings for all users, if available, and clear the same compatibility option there. A machine-wide setting can remain active after the first checkbox has been cleared.
- Apply the change and run the file again. If a boxed DVD starts through
autorun.exe, bypass it and launchsetup.exedirectly. Checkautorun.exeas well if the warning appears before the main installer opens.
Running boxed setup.exe as administrator can help with file permissions, but administrator access and compatibility mode are separate settings. Administrator access alone will not correct the XP SP2 version check.
Which FSX file should I change?
The file to change depends on when the XP SP2 message appears.
| When the error appears | File to inspect | Correct action |
|---|---|---|
| Before boxed FSX begins installing | autorun.exe and setup.exe on Disc 1 | Clear compatibility mode, then start setup.exe directly. |
| When an installed boxed copy starts | The installed fsx.exe | Clear compatibility mode on the executable and check the shortcut target. |
| When FSX: Steam Edition starts | Steam Edition’s installed fsx.exe | Clear compatibility mode; verify the installed files if the warning remains. |
| On a genuine pre-SP2 Windows XP computer | The operating system itself | XP SP2 or SP3 meets the historical requirement, but Windows XP is unsupported and should not be used online. |
What if compatibility mode is already unticked?
If compatibility mode appears to be off, the usual cause is a setting attached to another copy of the file, the shortcut or the all-users compatibility layer.
- Confirm the full file path. A shortcut may point to an old or duplicate FSX installation. Open the shortcut’s target location and inspect that exact
fsx.exeorsetup.exe. - Inspect both sets of properties. Check the shortcut and the executable, then use Change settings for all users on the executable. Reject any Windows prompt offering to rerun FSX with recommended XP-era settings.
- Check stored compatibility flags. Advanced users can inspect
HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layersand the equivalentHKEY_LOCAL_MACHINEpath. Export the key before changing it. Remove only a value whose name exactly matches the affected executable’s full path and whose data applies an old-Windows compatibility layer. - Restart Windows. Run the same executable again after the compatibility entry has been removed.
If there is no exact matching registry value, change nothing. Do not edit Windows version information, delete unrelated compatibility entries or download Windows XP SP2 for a Windows 10 or 11 computer.
Reinstalling FSX before clearing the flag often achieves nothing: Windows can retain a compatibility layer against the same executable path even after the simulator has been removed.
Does this error mean I need FSX Service Pack 2?
No. Windows XP Service Pack 2 updates the operating system, while FSX Service Pack 2 updates Flight Simulator X. The similar names refer to different products.
Once unexpanded boxed FSX installs, FSX Service Pack 1 normally precedes FSX Service Pack 2. Acceleration follows its own update route, while FSX: Steam Edition must not receive the standalone boxed-edition patches. Our FSX service-pack and edition update guide explains which path applies.
Can FSX run on Windows 11 without XP compatibility mode?
Yes. FSX can run on Windows 11 without making the executable pretend that Windows is XP, although old add-ons and boxed media can require separate attention.
Do not apply XP compatibility to the entire simulator merely because one old add-on has trouble. We cover the sensible installation choices and limitations in our guide to running FSX on a modern Windows 11 PC.
What if FSX still will not install or start?
If the exact XP SP2 warning remains, recheck the executable path and the all-users compatibility setting; one of the relevant files is still being launched under a legacy Windows layer.
If the XP warning has disappeared but FSX now reports a different message or error code, the compatibility problem is fixed. Treat the new error separately rather than restoring XP mode. Steam Edition users should verify the installed files, while boxed-edition users may need to repair a partial installation or rerun Disc 1’s setup.exe; our FSX file repair steps for boxed and Steam installations cover the appropriate next checks.