Why does my PC restart in a flight simulator?

A PC that fully restarts while launching or flying a flight simulator is usually hitting a system-level fault, not an ordinary simulator crash. The leading causes are an unstable power supply, CPU or GPU overheating, overclocked RAM or processors, graphics-driver failure, or a Windows blue screen hidden by automatic restart.

This applies across general PC flight simulators, including Microsoft Flight Simulator, X-Plane, Prepar3D and FSX. First confirm that Windows actually reboots and displays its boot screen. A black monitor with continuing sound may instead be a graphics-driver, display-cable or GPU failure.

What does the restart timing reveal?

The point at which the restart occurs can narrow the fault before any hardware is replaced.

Simulator menus can produce unexpectedly high frame rates, while scenery loading may place the CPU and GPU under heavy load together. That explains why a marginal PC may restart at the menu or loading screen even though less demanding software appears stable.

How do I diagnose a flight simulator PC restart?

Work through reversible stability checks first, changing only one thing at a time so the result remains meaningful.

1. Reveal any hidden blue screen. Search Windows for View advanced system settings, open Startup and Recovery, and clear Automatically restart. If the next failure displays a stop code, record it. This setting cannot expose a sudden PSU power cut, but it separates many driver and memory crashes from power loss.
2. Check the Windows evidence. Open Reliability Monitor and the System section of Event Viewer around the exact restart time. Look for bug checks, WHEA-Logger hardware errors, display-driver failures or LiveKernelEvent entries before the shutdown. Do not treat Kernel-Power Event 41 as the diagnosis; it usually records only that Windows did not shut down cleanly.
3. Remove all performance tuning. Return the GPU to its standard clock and voltage, disable CPU tuning, and test the memory without XMP or EXPO. These memory profiles are overclocks, even when supplied as a one-click setting. An undervolt can also be unstable under the mixed CPU and GPU workload produced by a simulator.
4. Inspect temperatures and cooling. Use a hardware monitor to watch CPU temperature, GPU temperature, GPU hotspot and fan speed during loading and flight. Check that fans spin, vents are clear and any liquid-cooling pump is operating. Compare readings with the limits specified for the exact processor and graphics card rather than relying on one universal temperature threshold.
5. Check power delivery. Shut down and disconnect the mains before reseating accessible GPU and motherboard power connectors. Use the cable arrangement required by the graphics-card and PSU manufacturers; a loose connector, unsuitable adaptor or overloaded shared lead can fail during a load spike. Rated wattage alone does not prove a PSU is healthy, particularly if it is old or low quality. On a laptop, test with the original correctly rated power adaptor and inspect battery health.
6. Repair the driver layer. Install a stable graphics driver cleanly, or roll back if the restarts began directly after a driver change. Update supported chipset drivers and firmware separately so each change can be tested. If Microsoft Flight Simulator reports a graphics-device warning before failing, follow our steps for diagnosing MSFS graphics-device failures.
7. Test memory at standard speed. Run an extended memory test, beginning with Windows Memory Diagnostic if no other tool is available. Any error matters. If qualified to work inside the PC, testing one module at a time can identify a faulty stick or slot; otherwise, have a technician perform this step.
8. Return the simulator to stock. Disable plug-ins, overlays and third-party aircraft or scenery, then verify the simulator files and reproduce the same flight with default content. For Microsoft Flight Simulator 2020 or 2024, our MSFS-specific checks for freezes and system restarts cover its caches, Community content and graphics workload.
9. Compare isolated and combined loads. A short CPU-only test that fails points towards CPU cooling, voltage, RAM or motherboard stability. A GPU-only failure shifts suspicion towards the graphics card, its driver or power cables. If both pass separately but the combined load restarts the PC, the PSU, motherboard power delivery or case cooling becomes the leading suspect. Stop immediately if temperatures rise abnormally, visual artefacts appear or there is any smell or electrical noise.

Lowering graphics settings or capping the frame rate is a useful test, but not a permanent repair for unstable hardware. If reduced load merely delays the restart, the underlying power, cooling or stability problem still exists.

Is Kernel-Power Event 41 the cause?

No. Kernel-Power Event 41 means Windows detected that the previous shutdown was unexpected; it does not identify what caused it.

A bug-check entry or dump points towards a Windows, driver or memory crash. WHEA errors can implicate the CPU, RAM, PCIe bus or other hardware. If Event 41 appears with no useful event immediately before it, abrupt power loss is more likely, although a severe lock-up can also prevent Windows from writing the real error.

Can a flight simulator add-on restart the PC?

An add-on can trigger the workload or software path that exposes the fault, but a healthy PC should not hard-reboot because scenery or an aircraft is demanding.

Bad content more commonly causes a freeze or crash to desktop. If the simulator closes while Windows remains running, use the software-level MSFS crash checklist rather than treating it as a power failure. A restart tied to one add-on still warrants testing at stock clocks and checking drivers, RAM, temperatures and power delivery.

Stop testing and inspect hardware safely

Stop testing immediately if the PC smells hot or burnt, makes electrical clicking sounds, shows a damaged power connector, or repeatedly loses power under light loads. Do not open a power supply; its internal components can retain dangerous voltage.

The most decisive PSU test is substitution with a known-good, correctly rated unit using only that unit’s own modular cables. If you cannot do this safely, a repair technician should test the PSU, graphics card and memory rather than repeatedly forcing restarts that may corrupt files or damage a failing connector.