Putting your PC into sleep mode manually or automatically can have several advantages. Technically, it is a low power mode, and sleep, suspend or stand by are all referring to the same mode.
What happens in the background is that the last state of the system is stored in RAM before power gets cut to all devices and systems that are not necessary for this minimal mode of operation.
The state is resumed when you hit the wake button, or when the keyboard or mouse are moved.
Sometimes, the computer comes out of sleep mode without you doing anything. This can have several causes, and this guide discusses several of them.
The first thing you should do is try and determine the source or device that is waking up your PC. Windows ships with several tools that you can use for the purpose, and this part of the guide explains how you can use them to find out more about the source.
Note that while it may reveal information to you, it is not always the case. It can happen that the diagnostic programs return no sources at all, or only unknown sources.
Still, it is a good idea to start here as a hit will provide you with the information needed to prevent that the computer wakes up automatically while in sleep mode.
Command line diagnosis
First thing you may want to do is check whether devices are responsible for waking up the computer automatically. Do the following to find that out:
Windows Event Viewer diagnosis
While still on the command line, type eventvwr.msc to launch the Windows Event Viewer.
This is the part where we apply the fix, to prevent that sleep mode is left automatically. If you have discovered what is responsible for it on your system, skip all suggestions except for the one that matches your issue.
If you do not know the particular source, try them all to find out more about it. I suggest you try one solution, put your PC into sleep mode, and see if it recovers from that automatically. If it does, that was not the solution for your issue, and you should go to the next suggested fix and try that.
Fixing the mouse
The computer mouse may be responsible for bringing the PC out of sleep mode. You can find out if that is the case, and disable the feature, in the following way:
Alternatively, open the Device Manager from the desktop Control Panel, locate the Mice and other pointing devices listing here, and right-click on the devices listed under it to select properties there. Or, simply double-click on the device in question.
Here you get the power management options directly, without having to go through the lengthy process described above.
Fixing Wake Timers
If a wake timer is responsible for waking your PC, you may want to check out the application that is responsible for that to prevent it from waking up your PC.
If you do not want any wake timers to be used, it is possible to disable the feature completely.
Make sure you make the change for all available power profiles.
Fixing network cards
Network adapters may wake the PC as well. You can check how the installed adapters are configured by running the following commands:
Side tip: You may also want to check your BIOS configuration for "wake on ring" and "wake on LAN" settings if available, and disable those.
Scheduled Reboot Task
On Windows 10, you will find that a reboot task may wake the computer up to install updates for the system and will wake up the computer even if no updates are available at that time.
To disable the task, do the following:
This is not enough however as Microsoft will re-enable it again in the future. To avoid this, it is necessary to change the permissions of the task on the operating system level.
Automatic Maintenance
Some versions of Windows are configured to run automated maintenance tasks. While you may not want to disable those completely, it makes sense to set them to a time of day that works for you.
Command line Fu
Here is a list of useful commands that can help you find out more about your PC's sleep mode and wake up configuration:
Powershell
Run the command powershell from the command line to activate it.
Useful resources
If you want to know more about the sleep and wake functionality, use the following resources as a starting point:
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Ghacks is a technology news blog that was founded in 2005 by Martin Brinkmann. It has since then become one of the most popular tech news sites on the Internet with five authors and regular contributions from freelance writers.
Does Microsoft’s automatic update wake a PC from sleep ?
Yes it can do that.
Yup, it wakes it up for any auto updates including optional ones we need to acknowledge to install. Though I wish there was an ignore or opt out option for some of those optional updates so it never wakes the computer again. I put the computer to sleep and the moment I walk away it boots up again. I check all settings as suggested by Martin and the only thing still on the list as on are the optional updates which I already installed with the exception of the stupid Bing Bar… I hate any toolbar. Why buy a large screen monitor (27″), only to have the majority of the screen taken over by useless toolbars. I don’t even have the browser toolbars or bookmark bar up. Only the URL box and any icons that can launch from that line.
“powercfg -devicequery wake-armed” needed to be “powercfg -devicequery wake_armed” on my win 8.1 machine (note the underscore)
Thanks so much for this article. My PC constantly wakes itself and I hadn’t been able to figure out why. Now I know where to look.
You are right, it needs to be an underscore. I have edited the guide. Good luck with the troubleshooting!
Ever since 8.1 my PC has occasionally (not sure why only sometimes) been refusing to sleep (worked fine on 8), which while researching I have recently learned the commands above. While I suspect MS will shortly release a fix to my issues, it’s great to use the above tips to help determine an obvious root cause. Thanks for the excellent write up as I’ll keep it for a future reference!
Do you have a guide to sort out what prevents a system from enabling a screen saver/power save on monitors?
No unfortunately not at this time. I can’t promise anything but I check it out to see if I can find out enough about it to write a guide.
Martin – just wondering if you’ve found any good troubleshooting for the screen saver yet?
My case I don’t want this machine to sleep (yes, never) but I would like it to do the screen saver and then turn off the monitor.
So far I’ve discovered that if I have a powershell window open and at the front/active, that my screen saver *will* turn on, but then seconds later will come back from it. I’ve been searching off and on for a month but not finding a good and concise troubleshooting list as you have done for “sleep”.
Either way, thank you for a very well written and time proven re-usable sleep guide!
(fwiw – windows 10 pro, standard release branch, amd ryzen processor, gigabyte aorus rx580, 1x512g SSD primary, 1x3tb secondary drive, 1xCDr/w drive)
I have the opposite problem. The computer will not wake from S3 sleep properly. The fans spin up, HDD activity light flicks on for a second, but the screen stays blank, with no mouse or keyboard activity. The power button doesn’t soft-shutdown the computer as it is programmed to; it only does the four-second hard shutdown. I’ve disabled hybrid sleep as this seems to be a common fix, but it hasn’t solved the problem. All Event viewer says is that the computer recovered from an abnormal shutdown.
I’m tearing my hair out trying to fix this one. Any ideas?
I suppose you have checked this article? http://support.microsoft.com/kb/266283
The various tasks running in the OS Task Scheduler are majorly responsible for waking PCs. It’s a good idea to check those too. :)
Thanks
Windows 8 especially wakes it up for any auto updates including optional ones we need to acknowledge to install. Though I wish there was an ignore or opt out option for some of those optional updates so it never wakes the computer again.
I put the computer to sleep and the moment I walk away it boots up again. I check all settings as suggested by Martin and the only thing still on the list as on are the optional updates which I already installed with the exception of the stupid Bing Bar…
I hate any toolbar. Why buy a large screen monitor (27″), only to have the majority of the screen taken over by useless tool bars. I don’t even have the browser tool bars or bookmark bar up. Only the URL box and any icons that can launch from that line.
This is a great article because it has teached me something that I didn’t t know before. Unfortunately, it hasn’t helped me because event viewer attributes all my unexpected night wake-up events to an “unknown device”.
Sometimes it’s not even the computer. I finally figured out what was causing mine to wake up. Every time someone uses the ventilation fan in the adjacent bathroom it will bring my desktop out of sleep mode. My office is adjacent to this bathroom and I guess the outlet and the bathroom fan are on the same circuit.
Thank you, Martin. Very useful guide.
Very nice. Thanks
Thanks for the informative article. I have searched in lots of forums and sites but except your guide nothing worked. Keep going. Expecting more articles in the future. :)
Verizon In Home Agent was the cause of my frustration. After disabling mouse, keyboard, and NIC wakeup parameters PC would still wake every minute. Finally, the command powercfg /waketimers showed that IHA was scheduling a waketimer each 60 sec. Uninstalling this app resolved the problem. Happy surfing…
So what do I do if “Wake Source: Unknown”?
Is there any way of determining the unknown source?
One diagnostic tool (at least as to WHEN your computer is waking up and how often) is winSleep by mollieSoft – see http://www.molliesoft.com/winsleep. It shows a timeline of when your computer was awake or asleep over the last several days (or even further back) so can give you a clue as to what is waking it up and when.
In my case, with the command lastwake I could discover that a .exe (Core.exe, from Warsaw – GAS Bank Security) is the reason of my wake ups. Any suggestion about how to avoid a executable to bring my PC up?
Thanks
Same here, Thiago.
Let me know if you find any way to fix this:
powercfg -lastwake
Contagem de Histórico de Ativação – 1
Histórico de Ativação [0]
Contagem da Origem de Ativação – 1
Origem de Ativação [0]
Tipo: Timer de Ativação
Proprietário: [PROCESS] \Device\HarddiskVolume4\Program Files\Diebold\Warsaw\core.exe
Razão Fornecida do Proprietário: generic
Hi, thanks followed the instructions here and managed to understand that it was popcorntime’s TTmedia service that was waking my computer every time i powered it down!
thank you
Thanks alot , It solved my problem through this command :
powercfg -waketimers
I found the reason of powering on , and disabled that task in “Task Scheduler”
thanks alot !
nice solution/website
Thanks
Excellent writeup. Concise and easily followed. I hope my changes will stop my computer from waking up again. I hate when I see issues like this as I’ve been out of the loop in building and diagnosing computers for a while. Thanks!
This is the best writeup I’ve found on the topic. I particularly liked how you called out the Advanced tab in Device Manager, as well as suggesting to check the BIOS. I’ve only ever heard of going to Power Management. I hope that does the trick. Been so plagued by this. Will happily give a donation for such a good article.
Many years later, this article is super amazing and useful. Thank you so much!
I’m from 2020. This helped. Thank you kindly.