Hey folks,

Im running Windows 8.1 Enterprise (RTM) on a Dell Latitude E6320 Notebook. Since I installed Win 8.1 RTM I am not able to enter suspension modes, neither sleep nor hibernate, anymore. The screen will switch off, but there still is disk activity fitfully and it never really turns off the system. I was able to enter sleep and hibernate modes on the same machine with Windows 8.1 Preview (Although I had a load of other issues then :-))

If I enter hibernation from safe mode it will work like a charm so I figured one of the services blocked the system from suspension and I tried to identify which one by stopping and disabling the services. Unfortunately ended up with three services which are not running in safe mode, but also cannot be stopped on a normally booted system:

Group Policy Client
Task Scheduler
Windows Driver Foundation

So it could be one of them, but I dont know how to check this and even if I could identify the service I had no idea how to fix this, since they can not be disabled.

I also tried a selective startup from msconfig with all services disabled, but it did not work.

Additionally, I configured my power settings to disable hybrid sleep.

It doesnt make any difference if I have any additional devices, like wireless mouse or keyboard, USB-sticks or external monitors connected, also it will not work with or without external power.

I tried to disable my display driver.

I updated all my drivers (chipset drivers, display, sound, etc.) with no success.

Its really bugging me and I already invested so many hours to fix this. I am really getting desperate here and any hints, ideas, workarounds or solutions are greatly appreciated.

Thx
Fabio