Fix PC Waking Up From Sleep Randomly

Does your Windows PC wake itself up from sleep in the middle of the night? Here's how to find out what's causing it and stop it for good.

Published 2026-02-04 by TechNet New England

You put your computer to sleep, walk away, and come back to find it awake again with the fans spinning and the screen on. Maybe it happens every night at 2 AM, or maybe it wakes up randomly a few minutes after you close the lid. Either way, something is telling your PC to wake up, and Windows makes it surprisingly easy to find the culprit.

Step 1: Find Out What Woke Your PC

Windows logs what triggered the last wake event. Open Command Prompt or Terminal as administrator and run:

powercfg /lastwake

This will show you the device or event that caused the most recent wake. Common results include network adapters, mice, keyboards, or scheduled tasks like Windows Update.

For a full list of devices that are allowed to wake your PC, run:

powercfg /devicequery wake_armed

This shows every device that has permission to bring your computer out of sleep.

Step 2: Disable Wake Timers

Wake timers are scheduled tasks that are allowed to wake your PC from sleep. Windows Update and some other system tasks use these by default.

  1. Open Control Panel > Hardware and Sound > Power Options
  2. Click "Change plan settings" next to your active plan
  3. Click "Change advanced power settings"
  4. Expand "Sleep"
  5. Expand "Allow wake timers"
  6. Set both "On battery" and "Plugged in" to "Disable"
  7. Click Apply, then OK

Step 3: Disable Wake-on-LAN

Wake-on-LAN is a feature that lets your network adapter turn on the PC when it receives a specific signal. This is useful in office environments where IT needs to push updates to machines overnight, but for home use it often just causes random wakes.

  1. Open Device Manager
  2. Expand "Network adapters"
  3. Right-click your Ethernet or WiFi adapter and select "Properties"
  4. Go to the "Power Management" tab
  5. Uncheck "Allow this device to wake the computer"
  6. Click OK

If you also see options like "Wake on Magic Packet" or "Wake on Pattern Match" under the "Advanced" tab, you can disable those as well.

Step 4: Stop Your Mouse and Keyboard from Waking the PC

A bumped desk or a cat walking across the keyboard can wake your computer. If you want to prevent this:

  1. Open Device Manager
  2. Expand "Mice and other pointing devices"
  3. Right-click your mouse and select "Properties"
  4. Go to the "Power Management" tab
  5. Uncheck "Allow this device to wake the computer"
  6. Repeat for your keyboard under "Keyboards"

Note: If you disable wake for both mouse and keyboard, you'll need to press the physical power button to wake the PC.

Step 5: Check for Scheduled Tasks

Some scheduled tasks are configured to wake the PC. To find them:

  1. Open Command Prompt as administrator and run:

powercfg /waketimers

This shows any active wake timers. If you see a specific task listed, you can open Task Scheduler (search for it in the Start menu), find that task, right-click it, select Properties, go to the Conditions tab, and uncheck "Wake the computer to run this task."

If these steps don't resolve the issue, or if you'd like professional help, our team is here. Contact TechNet New England for IT support.