Windows 7: Since 9/16/2012, computer wakes from sleep in 2-3 minutes

I've got a pretty regular and predictable usage pattern with my computer - quick logon in the morning to check emails, go to work, use computer at night, restart before bed.

The computer is set to sleep after three hours of inactivity. So in the morning it will be sleeping, then when I get home from work same thing. Sometimes not; never figured what wakes the computer, but 90% of the time, that's how that works - it sleeps after three hours, and stays sleeping for several hours.

However, this week I noticed that the computer seemingly never sleeps. It's always on when I come by it, including in the morning, and when I get home from work.



Checked the system log in the event viewer for events 1 (wakeup) and 42 (sleep), and I noticed that, into the morning of 9/16, the normal pattern of several hours of sleep was adhered to. Since 9/16 though, every sleep period lasts about 2 1/2 minutes. That is, it goes to sleep (event 42), and then within 2-3 minutes, it will wake up (event 1).

There have been no Windows updates in that time that would affect this. Definition updates for Windows Defender on 9/18 and 9/21, and KB2744842 (security update for IE 9 on x64 systems) on 9/22, but nothing happened, including no new software installations, on 9/15 or 9/16.

So why is my computer suddenly waking from sleep almost immediately?

Hello 450125,

The next time it wakes up like that, you might run the lastwake command to see if it may be able to help ID what woke the computer up.

Lastwake Command

Hope this helps for now,
Shawn

Thanks Shawn.

I'd tried that before. And I tried it today after reading your suggestion.

All the lastwake command gives me is "Wake History Count - 0"

If I look at the event viewer, every wakeup I see - I went back a week looking at every wake, then just randomly checked wakes before that - said "Wake Source: Unknown"

In that case, you might also go through the steps in the tutorial below to see if it may help reveal a cause.

Power Options and Sleep Mode Problems - Vista Forums

Also Unplug your mouse and KB too see if its these that is causing it, Also have you got Wake on lan enables in the BIOS.

Thanks. I did check things in device manager as the tutorial suggested.

According to powercfg -devicequery wake_armed from my computer, the only device that can wake it is Realtek PCIe GBE Family Controller

I'm going to be away for several hours - the computer should sleep. Will report back as to what happened when I was gone.

Was gone for 5 1/2 hours and the computer, set to sleep after 3, never slept in that time.

Hmm, sounds like something is running preventing it from sleeping.

When you have time, you might shorten the wait to sleep timeout period, then see if troubleshooting using the tutorial below to see if it will sleep after each test.

Troubleshoot Application Conflicts by Performing a Clean Startup

I turned off the network controller's ability to wake the computer. What important functionality will I lose by doing this?

I'm going to bed, so we'll see how the computer is in the morning.

Ok, get some rest. I'll be here tomorrow.

The wake-on-LAN feature allows you to be able to wake your computer remotely.

Wake-on-LAN - Wikipedia, the free encyclopedia