Both hibernation and standby mode are popular methods of shutting your PC down. Much less so however, is their tendency to wake up again at the slightest provocation. Here's how you can both find and eliminate the cause.
Get to the bottom of mysterious midnight-boot-ups
Hibernation and Standby mode can both be seen as gentle ways of putting your PC to sleep. Since all data from your current work session is saved in your hard drive or memory for repeated use, turning your system off and on again requires much less time than it would with a conventional shutdown process. Unfortunately, this method tends to have a major side effect: Unexpected and unwanted boot-ups, often in the middle of the night. What's worse, finding the cause often compares to searching for a needle in a haystack and can lead to lots of frustration. No need to stumble in the dark, however - here's how you can narrow down and identify the cause systematically.
Most typically, the culprit can be found in your internal and external peripheral equipment, such as your mouse, your keyboard or even your network card. Windows often equips many of these devices with the ability to wake your PC up if there is an input signal. If so, any activity, even as miniscule as an unintentional bump of the mouse, will inevitably disturb your PCs nap and cause him to rise from his slumber. Alternatively, a lot of security programs tend to schedule their updates to times at night, which is also a common cause for the problem. See also: How to activate hibernation mode in Windows 7 and 8
1. PC waking in sleep mode: Finding the Problem
A) Via the command line tool
To quickly find out which one it is, you will need to summon your command prompt with administrative rights. To do so in Windows 7, search for “cmd” in your Windows search bar, right-click it and select “Run as Administrator”. In Windows 8, simply hold down the Windows-key + X and select the option “Command Prompt (Admin)” from the menu. In the following prompt, enter the line
powercfg - lastwake
to identify the event or device that is responsible for the last waking process. Once the results are shown, check the “Instance Path:” to see where it originated from (the USB or PCI port for instance) and look under “Type:” for the nature of the cause, typically a device or a wake timer. You can find solutions for both cases further in the solutions section of this article.
Tip: Disabling the wake-up function of one device is usually enough to prevent accidental boot-ups in the future. If you'd like to make absolutely sure that your PC stays put however, you might also want to have a look at all other devices that can potentially wake him up. To get an overview, enter
powercfg -devicequery wake_armed
into the prompt. Conversely, you can also get a complete list of all devices that can be programmed with a wake-up function by entering
powercfg -devicequery wake_programmable
into the prompt - for instance, if you'd like to find out whether or not your keyboard can be turned into a second power button. In either case, note down the names of all devices that you want to add or remove from the wake-up list and jump to the solution section further below.
B) Via the Windows Event Viewer
If the approach with the command prompt hasn't yielded any (interpretive) results, you can also try looking for the cause in the more user-friendly Windows Event Viewer. To open it, hold down the Windows-key + R and type in “eventvwr.msc”.
Once inside, click on the little arrow next to “Windows Logs” in the left panel to expand its contents and select the entry “System”. As the number of events often rank in the thousands, this might take a little while to process. Look on the right side for an option called “Filter Current Log” to filter them according to certain criteria. Look for the drop-down menu “Event sources” and select the entry “Power-Troubleshooter” from its long list of options and click on “OK”.
This will give us a compact overview of all recent wake up events with both date and time in the middle of the Event Viewer. Simply check all the suspicious ones for the “Wake Source” to see what caused the disturbance.
Also take a look at: How to shut down Windows 8 with your computer's power button
2. PC waking in sleep mode: Solving the Problem
A) If a device is the cause
If your wake source is listed as a device, the problem typically lies with your mouse or keyboard, though network cards are also infamously known to cause inexplicable wake-ups. In either case, head into your device manager by holding down the Windows-key + R and enter “eventvwr.msc”. In the device manager, search for the the device in question, right-click it and select “Properties”. Then simply switch to the “Power Management” tab and uncheck the box for “Allow this device to wake the computer”.
In case you want to add or remove this function from other devices as well (as described above), search for them in the device manager and (un)check their boxes in the same manner.
Note: The same result can be achieved with the help of the trusty command line tool. Tough obviously more complex, you can give this method a shot if the box for the wake-function is grayed out in the device manager and can't be modified as a result. Make sure to start the command prompt with administrative rights and enter either
powercfg -devicedisablewake “[devicename]”
powercfg -deviceenablewake “[devicename]”
B) If a wake timer is the cause
If a program wants to schedule regular maintenance, it typically asks Windows to reserve a wake timer for a specific time and/or day of the week. This automatically causes your PC to wake up, download the necessary files and apply the updates. While this could be considered a useful function in theory, more often than not, Windows neglects to shut itself down again after the process has finished, thus staying up all night and wasting precious energy.
To get an overview over all active wake timers, pop up your command line tool again (with administrative rights), and enter the line
If the name of the program that is causing the disturbance can be clearly discerned from the results, its usually enough to open it up and modify or deactivate the updating routines manually. If not, or if there are simply too many wake timers active to bother with them individually, you can just deactivate them altogether.
To do so, hold down the Windows-key + R and enter “powercfg.cpl” to bring up the “Power Options” of Windows. Click on “Change plan settings”, followed by “Change advanced power settings” in the next section to open the “Advanced settings” window. Expand the entry called “Sleep” as well as its submenu “Allow wake timers”. Depending on whether you are using a laptop or a PC, you will likely see either two or just one option at this point. In any case, just set them to “Disable” and troubling wake timers should be a thing of the past.