It’s late at night. You want to hit the hay and, planning to immediately resume your work the next day, you put your computer into sleep mode. But not long after it went to sleep, you find the computer has woken up on its own. What has caused this unexpected boot-up?
To find out, open the Command Line by pressing Windows+R, typing cmd, and pressing Enter. In the Command Prompt, type powercfg -lastwake. This particular command displays a report about the hardware component that woke your computer from its last sleep transition. It could be the mouse, keyboard, or wake timer. If you pressed the power button to wake the computer, the command would report as such.
If the command above fails to properly identify the cause, try using the power -devicequery wake_armed command instead. This lists all devices that are authorized to wake the computer.
Once you find out the culprit, go to the Device Manager in the Control Panel. Locate the specific hardware you read in the command line report. Right-click it and select Properties. Under the Power Management tab, uncheck Allow this device to wake the computer.
If the command line reported a wake timer as the cause, go to the Power Options in the Control Panel instead. Click Change plan settings of the power plan that your computer is currently using. Click Change advanced power settings. Scroll down the list until you find Sleep, expand it and expand Allow wake timers. Select Disable and click Apply to save the change. At this point, software-related events should no longer be able to wake your computer.
In many cases, the cause of the problem is an overly sensitive mouse. Sometimes, it’s a software program that’s automatically scheduled to check and download updates. Or it could be a loose USB port that disconnects devices and immediately reconnects them back, causing your computer to wake up from sleep mode.