I too had a similar issue. I'm posting because this thread is one of the top results Google gives for Windows 10 sleep problems.
The solution that worked for two computers I had that were not sleeping was as follows:
- Run an admin command prompt
- powercfg -requests
- This command lists all processes or services currently running that are preventing the computer from sleeping. The list is helpfully broken down by categories. One of my affected computers had sleep blocked by the IncrediBuild component of Visual Studio,
the other by a different TSR program.
I did this and found this:
"C:\WINDOWS\system32>powercfg -requests
DISPLAY:
None.
SYSTEM:
[DRIVER] NVIDIA High Definition Audio (HDAUDIO\FUNC_01&VEN_10DE&DEV_0083&SUBSYS_145836FE&REV_1001\5&1d6e7f53&0&0001)
An audio stream is currently in use.
[DRIVER] USB Audio Device (USB\VID_0951&PID_16A4&MI_00\6&3321d09b&0&0000)
An audio stream is currently in use.
[DRIVER] Legacy Kernel Caller
AWAYMODE:
None.
EXECUTION:
None.
PERFBOOST:
None.
ACTIVELOCKSCREEN:
None.
C:\WINDOWS\system32>"
I did some checking and those drivers listed under SYSTEM is my USB headset (HyperX Cloud II); it says "None" when I unplug the headset. Although, I don't understand why this would be preventing sleep.
- The "allow computer to sleep" under the multimedia section, as many have talked about here already, is selected.
- This problem hasn't occured until recently. I have had this headset for almost 2 years and only now is my PC having an issue with sleeping after idle (been using Win10 the entire time as well).