Windows Registry Key for Auto Restart on Failure

This article explains the Windows Registry keys that manage automatic system restarts and thresholds during system and power-related failures. While initial hardware recovery after an abrupt electrical loss is controlled by BIOS/UEFI firmware, the Windows operating system uses specific registry values—principally within the CrashControl and Power keys—to manage how the machine behaves, reboots, and triggers thresholds when critical power or system failures occur.

Primary Registry Key for Automatic Restart

To manage the operating system’s automatic reboot behavior when a critical system failure occurs, Windows uses the CrashControl key:

• Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\CrashControl
• Value Name: AutoReboot
• Data Type: REG_DWORD
• Value Data:
  • 1 = Enabled (Windows will automatically restart upon encountering a fatal system failure or crash).
  • 0 = Disabled (Windows halts at the error screen without restarting).

Critical Battery and Power Threshold Settings

When managing automated system actions triggered by battery and power drop thresholds on supported devices, the power policy registry subkeys define the operational limits:

• Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\e73a048d-bf27-4f12-9731-8b2076e88088\9a66d8d7-43e3-4767-87a3-7b5a7066cb52
• Function: Controls the Critical Battery Level percentage threshold that dictates when automated critical actions (such as shutdown, hibernate, or restart) are initiated.
• Value Name: SettingValuePossible / active profile subkey settings.

To configure the action taken once this threshold is reached: * Subkey GUID: 637ea02f-bb61-4ea2-a56e-05dad6097585 (Critical Battery Action) * Value Data: Sets the response to 0 (Do nothing), 1 (Sleep), 2 (Hibernate), or 3 (Shut down).

Hardware-Level AC Power Recovery

If the goal is to restart the physical machine immediately after wall power is lost and restored, this functionality is handled at the motherboard firmware level rather than inside the Windows Registry:

1. Enter the system BIOS/UEFI menu during startup.
2. Locate the Power Management or APM Configuration section.
3. Adjust the setting labeled Restore on AC/Power Loss, AC Back, or After Power Loss to Power On or Last State.

How to Modify the Setting in Regedit

1. Press Win + R, type regedit, and press Enter.
2. Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\CrashControl
3. Double-click the AutoReboot value in the right-hand pane.
4. Set the Value data to 1 to enable automatic restarts or 0 to disable them.
5. Click OK and restart the computer to apply the changes.