Windows Operating System








The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly.

The kernel power event ID 41 error occurs when the computer is shut down or restarts unexpectedly.  When a computer running Windows boots, a check is performed to determine whether the computer was shut down cleanly. If the computer was not shut down cleanly, a Kernel Power Event 41 message is generated. 

An event 41 is used to report that something unexpected happened that prevented Windows from shutting down correctly. There may be insufficient information to explicitly define what happened. To determine what may have happened and to identify a potential resolution, it is important to know what state the computer was in at the time just before the event occurred.



An event 41 can occur in the following scenarios:

Scenario 1: The computer restarts, and there is a Stop error BugcheckCode in the event data

When a Stop error occurs, the Stop error data is written in Event ID 41 as part of the additional event data. There may be the instances in which the Stop error code information cannot be written before the computer restarts or shuts down. Such instances are covered in scenario 3. 

Note The BugcheckCode data in the event is written in decimal format instead
 of a more typical hexadecimal format. Therefore, the decimal value should be converted to a hexadecimal value.

If the Stop error BugcheckCode entry in the event ID data is not zero, you should convert the BugcheckCode value from decimal to hexadecimal. Most documentation on Stop error codes reference the code as a hexadecimal value instead of a decimal value.

To do this, follow these steps:

1. Click Start, and then type calc in the Search box.

2. Click View, and then click Programmer.

3. Make sure that the Dec option button is selected on the left side of calculator.

4. Use the keyboard to enter the decimal value from the BugcheckCode value.

5. Click the Hex option button on the left side of the calculator.

Note :  The value that the calculator displays is now the hexadecimal code. Repeat these steps for other nonzero values.

Scenario 2: The computer is shut down by pressing and holding the power button

  • The power button on the computer is pushed and held for at least four seconds. This action is noted in the event data as a PowerButtonTimestamp entry that has a value of something other than 0 (zero). There may be the instances where we cannot write the PowerButtonTimestamp information before the computer restarts or shuts down. Such instances are covered in scenario 3.

  • The preferred way to shut down Windows is to click Start, and then click an option to turn off or shut down the computer. In this case, the operating system closes all files and notifies all services and applications that are running so that they can write any data to disk and flush any caches.

  • If you have to press and hold the power button because of an issue that limits the ability of the computer to function correctly, you should run a query about the symptoms that you are experiencing so that you can get help with troubleshooting. Keywords that you might use in your search are "hang," "responding," or "blank screen."

Scenario 3: The system randomly restarts and no Stop error BugcheckCode is listed, or the computer is completely unresponsive (hard hang)

  • The Stop error code and the PowerButtonTimestamp are listed as zero. For example, consider the following scenarios:•The Stop error BugcheckCode value is listed as zero. Circumstances can prevent writing the Stop error BugcheckCode information before the computer restarts or shuts down. In this case, a BugcheckCode value of zero is logged. Also, perhaps no Stop error occurred, and the shutdown resulted from a power loss. For example, on a portable computer,
    this could mean that the battery is removed or completely drained. Or, on a desktop computer, this could mean that the computer was unplugged, or a power outage occurred.

  • The PowerButtonTimestamp is listed as zero. Circumstances can prevent writing the PowerButtonTimestamp information before the computer restarts or shuts down. In this case, a value of zero is logged. This can occur if the power button is pressed and held for at least four seconds when Windows has an operation
    running that prevents writing the event to disk. You might also see this scenario if the computer is “hard-locked” and therefore unresponsive to any input, and the computer has to be powered off.

To check whether this scenario is occurring, press the CAPS LOCK key on the keyboard. When you do this, if the CAPS LOCK light on the keyboard does not change when you press the CAPS LOCK key, the computer may be completely unresponsive (hard hang).

This scenario usually indicates a problem with the hardware and/or the devicedriver can cause this problem.

To help isolate the problem, check the following items:

1.  Overclocking: Disable overclocking to see whether the issue occurs when the system  is run at the correct speed.

2. Check the memory: Verify the memory by using a memory checker. Verify that each memory chip is the same speed and that it is configured correctly in the system.

3. Power supply: Make sure that the power supply has enough wattage to appropriately handle the installed devices. If you added memory, installed a newer processor, installed additional drives, or added external devices, such devices can require more energy than the current power supply can provide consistently.

4.Overheating: Check whether the system is overheating by examining the internal temperature of the hardware.

Additional Resources

Windows 7 Sleep Problem and Hibernate Options - see Troubleshooting section

How to Troubleshoot a Vista Sleep Mode Problem and Find a Solution

How to Troubleshoot a Vista Sleep Mode Problem and Find a Solution

How to enable and disable Hibernation - you can try disabling it and reenabling it.

How to disable and re-enable hibernation on a computer that is running Windows

How to Enable or Disable Hibernate in Windows 7

Sleep and hibernation: frequently asked questions