Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

How can I find out why my laptop or desktop won't automatically go to sleep

share|improve this question

migrated from May 26 '10 at 23:16

This question came from our site for system and network administrators.

Have you spilled coffee on it recently? OK OK that's lame... – Wayne Koorts May 2 '09 at 6:05
up vote 12 down vote accepted

I believe that Windows 7 is the only version of Windows which can tell you what devices are preventing the machine from sleeping. Windows 7 and Vista can tell you what devices are armed to wake the device from sleep.

There is a tool called powercfg which can do this. New to Windows 7 is the ability to see what is armed.

Windows 7

  1. Open an elevated command prompt
  2. Type powercfg /requests

You will see a list of items preventing the machine from entering sleep.

share|improve this answer
Those commands should be used in conjunction with Kevin's answer to get a comprehensive list – Jader Dias Oct 5 '10 at 13:28

Vista also has powercfg.exe, which can tell you which devices are armed to wake the system from sleep:

powercfg -devicequery wake_armed

as well as which device last woke the machine from sleep:

powercfg -lastwake

Sounds like Windows 7 got some new features though.

share|improve this answer
Those commands should be used in conjunction with Omar's answer to get a comprehensive list – Jader Dias Oct 5 '10 at 13:27

you can also run powercfg -energy from an elevated cmd. this will monitor your PC for 60secs during which you should continue using it normally.

A report is generated at the end. Looking at Errors in this report should give you a clue as to what is preventing your PC from going to sleep.

one of the most common issues is Media sharing. This shows up as \Filesystem\srvnet in the report. You will need to turn off media sharing to get rid of this issue.

If its something different, do post any questions you have. thanks

share|improve this answer
The fact that \Filesystem\srvnet often prevents the system going stanby is correct. But setting Windows Media Player Network Sharing Service to disabled in the services MMC doesn't get rid of srvnet blocking standby. So I am a bit confused... – davor Aug 6 '13 at 8:59

There's also a Power-Troubleshooter source within Vista's Event Viewer in the Application event log with related information such as Wake Source.

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .