Just recently upgraded to Windows 8.1 a few days ago from Windows 8.
One thing I have noticed is that, even when on battery (using a laptop), if I'm idle the maintenance tasks run (they SHOULD only load when the laptop is plugged in), draining away my battery like nothing else. Curiously, I had a look in Task Scheduler for these tasks, and it turns out that they both had the setting "Start the task only when the computer is on AC power" is set to OFF. Tried setting them on, but whenever the tasks run again these settings reset themselves. Even disabling the tasks gets it reset to enabled.
Does anyone have any idea how to solve this? Thanks!

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