Fix FSX fullscreen problems on Windows 10 or 11, including black screens, wrong resolution, minimising, scaling and Alt+Enter failures.
To fix fullscreen problems in FSX and FSX: Steam Edition on Windows 10 or 11, press Alt+Enter to recover windowed mode, match FSX’s fullscreen resolution to the Windows desktop, disable DirectX 10 Preview, and restart. If needed, rebuild FSX.cfg, disable fullscreen optimisations for fsx.exe, and close overlays or focus-stealing utilities.
What should I try first when FSX fullscreen is not working?
Most FSX fullscreen faults can be isolated by changing one setting at a time in the following order.
- Return to windowed mode: Make FSX the active application and press
Alt+Enter. If the shortcut is ignored or immediately reverses itself, follow our Alt+Enter and window-focus troubleshooting steps. - Match the display resolution: Check the active resolution under Windows Settings > System > Display. In FSX, open the Display settings and Graphics tab, then select the same fullscreen dimensions and an appropriate refresh rate. With multiple monitors, make the intended FSX screen the primary display before launching the simulator.
- Turn off DirectX 10 Preview: Clear the
Preview DirectX 10option if it is shown, close FSX completely, and launch it again. This preview renderer can cause black screens, flickering and incompatible scenery or aircraft textures, particularly with older add-ons. - Rebuild FSX.cfg: Close FSX, rename the active configuration file rather than deleting it, and relaunch the simulator so it creates a clean copy. The boxed and Steam editions can use different names or roaming-profile folders, especially when both have been installed; our guide shows how to find the active FSX.cfg file. Display preferences and custom FSX.cfg tweaks will need to be reapplied.
- Test Windows fullscreen optimisations: Find
fsx.exein the FSX installation folder, open Properties > Compatibility, tickDisable fullscreen optimisations, and test again. If it was already ticked, untick it for one controlled comparison because graphics drivers do not all handle this Windows feature identically. - Remove anything that takes focus: Temporarily close recording overlays, GPU overlays, notification utilities and other applications that place messages over games. For FSX: Steam Edition, test once with the Steam overlay disabled.
Which fix matches my FSX fullscreen symptom?
| Symptom | Most likely fix |
|---|---|
| Black screen but FSX audio continues | Press Alt+Enter, disable DirectX 10 Preview, then rebuild FSX.cfg. |
| Image is cropped or menu clicks are offset | Match the Windows and FSX resolutions, then test the high-DPI override described below. |
| FSX opens on the wrong monitor | Set the intended monitor as the Windows primary display before starting FSX. |
| FSX repeatedly minimises | Disable overlays, notifications and background programs that steal keyboard focus. |
| Fullscreen flickers or changes colour | Disable DirectX 10 Preview and test without Windows HDR or variable-refresh features. |
Alt+Enter does nothing | Click inside FSX, close anything intercepting keyboard shortcuts, and try again. |
Why does FSX show a black screen only in fullscreen?
A black screen with sound still playing usually means FSX is running, but its legacy DirectX presentation mode has failed. Resolution or refresh-rate mismatches, DirectX 10 Preview, a damaged FSX.cfg and graphics overlays are the usual causes.
Recover with Alt+Enter, select a conservative resolution matching the Windows desktop, and restart FSX after changing the renderer. If the problem started immediately after a graphics-driver update, test the vendor’s next driver release or roll back to the previously working driver rather than reinstalling FSX first.
How do I fix FSX scaling and misplaced mouse clicks?
Incorrect menu size or displaced click targets usually point to Windows display scaling rather than a broken aircraft or scenery package. Right-click fsx.exe, open Properties > Compatibility > Change high DPI settings, enable the high-DPI scaling override, and test Application as the scaling method.
Use that override only for scaling symptoms. On a high-resolution display it can make menus physically smaller; if that is worse, revert the setting instead of combining several compatibility options.
Why does FSX keep minimising to the desktop?
Exclusive fullscreen minimises whenever another application takes focus. Repeated drops to the desktop are commonly caused by overlays, update notifications, recording tools, a pressed Windows key or another application opening a dialogue box.
Disable those items one at a time so the culprit remains identifiable. If uninterrupted operation matters more than exclusive fullscreen, a maximised window is a dependable workaround and makes task switching less disruptive.
Should I run FSX in Windows compatibility mode?
No—compatibility mode should not be the first fullscreen fix, especially for FSX: Steam Edition. It changes several Windows behaviours at once and can obscure whether the real cause is resolution, scaling, configuration or an overlay.
Likewise, run FSX as administrator only when resolving a confirmed permissions problem. Add-on programs communicating with FSX may then require the same elevation level, so administrator mode can create a second problem without repairing the display fault.
What if FSX still will not run fullscreen?
Test a stock aircraft at a default airport with one monitor active and all graphics injectors or overlays disabled. If that works, restore add-ons and display features individually; do not copy old FSX.cfg tweaks back as a block.
A mistake we see constantly is reinstalling FSX before testing a clean configuration file. Reinstallation often leaves the per-user settings responsible for the fault untouched. If FSX also fails in windowed mode, the problem is no longer specific to fullscreen; use our broader Windows 10 and 11 FSX display and launch checks.