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I have a big problem with my home theater PC that runs Windows 7 64Bit. Normally, I send that PC to hibernate every evening, but from time to time, it keeps waking up for no obvious reason, and stays on until I realize, which is sometimes half a day later :(

I have already checked for Windows update, which is not set to automatical, since I prefer installing updates manually.

When I look in the system event log, there is an entry called "Power Troubleshooter" which tells me that my system was reactivated at a specific time, but it also says:

Source = Unknown,

which is the most annoying part. So how can I actually figure out, which process reactivates the PC?

Is it possible to set a group policy which forbidds applications or services from scheduling tasks that allow waking up from hibernate at all?

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migrated from Jul 28 '11 at 19:35

This question came from our site for professional and enthusiast programmers.

Here are some things that might cause your computer to wake unexpectedly:

  • Opening the lid of your mobile PC

  • Moving the mouse or pressing a mouse button

  • Pressing a key on the keyboard

  • Network activity

  • Running a scheduled task

  • Plugging in or unplugging a universal serial bus (USB) device

  • Docking or undocking your mobile PC

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Hi,thanks for that hint, I can definitely exclude points 1, 2, 3, 6 and 7. I cannot guarantee for point 4 (network), but I am nearly sure that's not the reason, my network interface is not set to wake on LAN, but how can I be absolutely sure? Remains point 5, I have already looked at the task scheduler, but I find it rather unintuitive to find a task that is actually allowed to wake up the computer. Can you give me a detailed hint how such a taks might be found? – Erik Jul 28 '11 at 17:40
Hey, I did some digging and found this… – BeatShot Jul 28 '11 at 17:46
does it have an IR Sensor for a Remote Control? Some media PCs can be powered on via Regular Infrared remote. – cloneman Oct 19 '12 at 18:06

A task might be waking up the machine. You can open the Task Scheduler and disable your tasks one by one to find the culprit. You could also disable this type of wake up as follows:

  1. Control Panel
  2. System & Security
  3. Power Options
  4. Change Plan Settings (selected)
  5. Change Advanced Power Settings
  6. Sleep
  7. Allow Wake Timers
  8. Disable
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I had a problem like that in Vista. It was because of Media Center.

To answer your question, i dont know whether it is possible to set a group policy.

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Hi,thanks alot, can you tell me how you solved it in Media Center, which setting exactly was causing this behaviour? – Erik Jul 28 '11 at 16:39

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