Reboot at a random moment

The reboot is being recorded as a BlueScreen (bug check) even though no BSOD is visible. Windows can automatically restart so quickly on a stop error that the screen is never seen.

For random restarts and bug checks like this, the documented guidance is:

1. Treat it as a stop code/BSOD issue
   • Windows 10/11 may show only “Your device ran into a problem and needs to restart” briefly, then automatically restart. This is a stop code error (bug check / kernel error / BSOD) and can be caused by hardware, drivers, or software.
   • A specific stop code (for example, PAGE_FAULT_IN_NONPAGED_AREA or MEMORY_MANAGEMENT) and sometimes a module name are normally recorded with the error.
2. Check Event Viewer for Event ID 41 and related entries
   • In cases of unexpected restart, Event ID 41 (“The system has rebooted without cleanly shutting down first”) is often logged.
   • If Event ID 41 is present but BugcheckCode and PowerButtonTimestamp are zero, or Event ID 41 is missing, Windows might not have been able to write the error details (for example, due to power loss, hard hang, or disk write issues).
   • Also check for Event ID 46 from volmgr (“Crash dump initialization failed!”). If present, verify pagefile configuration because a misconfigured pagefile can prevent dump creation and bugcheck information from being written.
3. Systematically rule out common hardware causes When the system restarts or hangs without clear bugcheck data, Microsoft guidance is to suspect hardware first and perform these checks:
   1. Disable any overclocking and run the system at stock speeds; verify if restarts still occur.
   2. Check memory health and configuration with a memory checker; ensure all RAM modules run at the same speed and are correctly configured.
   3. Check the power supply:
      • Confirm it has sufficient wattage for CPU, GPU, drives, and peripherals.
      • Consider recent hardware additions (more drives, newer GPU/CPU, extra USB devices) that may have increased power demand.
      • If there are signs of power interruption (for example, power outages, loose power cable, drained or removed battery on a laptop), consider using a UPS on desktops.
   4. Check for overheating by monitoring internal temperatures and ensuring cooling (fans, heatsinks, airflow) is adequate.
   5. If running as a physical server, check whether any Automatic Server Recovery (ASR) or similar vendor tool is restarting the machine when it becomes unresponsive.
   6. If this is a Hyper‑V virtual machine, check whether the Hyper‑V heartbeat feature is restarting the VM when it stops responding.
4. Confirm dump creation so the exact bug check can be analyzed
   • Ensure a system or automatic memory dump is configured and that the pagefile is present on the system drive and large enough.
   • If Event ID 46 from volmgr appears, correct the pagefile configuration so future crashes generate a dump.
   • Once dumps are available (for example, in C:\Windows\Minidump), they can be analyzed to identify the specific driver or component causing bug check 0x133.
5. If the system is unresponsive before reboot
   • If the PC sometimes hard-hangs (no keyboard response, Caps Lock light does not toggle) and then is powered off manually, this also fits the scenario where Windows cannot write bugcheck data. In that case, the same hardware checks above apply.

Following these steps will help narrow down whether the random reboot is due to power/PSU, RAM, overheating, storage, or a specific driver, and ensure that the next occurrence produces a usable dump for detailed analysis.

References:

• Troubleshooting Windows unexpected restarts and stop code errors
• Advanced troubleshooting for Event ID 41: "The system has rebooted without cleanly shutting down first"