How to Fix a Computer that Keeps Waking Up

Not too long ago I bought a new desktop PC. Whenever I put it to sleep, in no time flat it was awake again. A little research revealed that this is not an uncommon problem and can have several possible sources. Malware infections are sometimes the cause but more often it is some device that is waking the machine up and that was the case for me. In this tip, I will describe several settings in your system that may keep waking up your PC. The discussion is for Windows Vista/7. You will generally need administrator privileges to make system changes.

Stop the mouse from waking up the PC

Mice, especially, wireless mice, can sometimes wake the PC up. In fact, there is a specific setting to allow this. If the mouse turns out to be a problem, you can change the setting with this procedure:
  1. Open the Start menu and type “mouse” (without quotes) in the Search bar
  2. Under the Control Panel list, click “Mouse” (or just press Enter in Vista)
  3. In the dialog box that opens, select the tab “Hardware”
  4. Highlight the entry for your mouse and click the button “Properties”
  5. A new dialog will open. Click the button “Change settings”
  6. In the new dialog that opens, click the tab “Power Management”
  7. Remove the check by “Allow this device to wake the computer”
  8. Click “OK” and close the dialogs.

Stop a network card from waking up the PC

From what I read, a network card is the most common source of wake-up problems and that was the cause of my own computer never staying asleep. Here is how to configure a network card:
  1. Open Device Manager. There are many ways to do this but a quick way is to enter “dev” (without quotes) in the Start search bar and click “Device Manager”
  2. Expand the list for “Network adapters”
  3. Right-click the adapter to be configured and choose “Properties”. There may be several adapters, one for Ethernet, one for wireless, and others like Bluetooth
  4. In the dialog that opens, click the tab “Power Management”
  5. Remove the check by “Allow this device to wake the computer”
  6. Click “OK” and close up Device Manager

Scheduled tasks , updates, and other causes

Sometimes a task or Windows Update is scheduled for a specific time and will wake up the computer. Dealing with these and other possibilities are discussed at this link.

Use the command line to find what causes the PC to wake up

One way to find out what is causing a wake-up problem is provided by the command line. Open a command prompt with elevated privileges and enter this command:
    powercfg –lastwake
The last device that woke up the system will be shown
To find out which devices are enabled to wake up the PC, enter this command
    powercfg -devicequery wake_armed