How do I determine the cause of resuming from hibernation in Windows 7?

Question

My notebook sometimes resumes from hibernation without any apparent reason. This happens only when its plugged in power, LAN connection does not influence it.

Is there some log that would tell me why it resumed (what timer or device) so that I can disable it? Or can I start logging of it?

Answer 1

You can use powercfg to find out what is waking up your computer.

1. Click on Start
2. Type cmd to open a command prompt
3. Type powercfg -lastwake

This will show you the particular USB or network device or event waking up your computer.