This morning, my computer was awake and humming though I know for certain that I put it in Sleep mode last night. The computer was updated to Windows 8.1 and I never caught Windows 8 having this behavior. To figure out why the computer was awake, I first checked out the event log.
Under the Windows Logs, System I was able to find an event from Power-Troubleshooter. It told me that the cause of the computer being awake was a scheduled task by the name of “Regular Maintenance”.
That led me to the Task Scheduler. There, I found the Regular Maintenance task listed under Active Tasks. If you double-click on the task or open the task’s properties, you can modify the settings under the Conditions tab such as ‘Wake the computer to run this task’.
You could uncheck the settings you don’t want but the conditions for a scheduled task can get fairly complex. I still wanted the “regular maintenance” to occur, I just wasn’t sure on when I was ok with it running. Looking into another alert, I opened the Action Center (the flag in your system tray). There, I found two categories: Security and Maintenance. Upon expanding maintenance, there is a line about Automatic Maintenance with the option to ‘Change maintenance settings”. This window matched the conditions I saw under the scheduled task but with fewer options and more explanation.
I ended up unchecking the box for “Allow scheduled maintenance to wake up my computer at the scheduled time” but feel more comfortable making the change here without losing too much benefit.
The explanation for Automatic Maintenance reads:
Windows automatically runs scheduled maintenance on a daily schedule when you’re not using your computer.
This includes tasks such as software updates, security scanning, and system diagnostics. This maintenance will run daily if you aren’t using your computer at the time you’ve chosen. If you computer is in use at the scheduled time or maintenance is behind schedule, Automatic Maintenance will run the next time the computer is not being used.