What is keeping my PC from sleeping?

Question

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

Answer 1

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.

Answer 2

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.

Answer 3

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

Answer 4

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