I recently started having a problem where my Windows 8 computer screensaver wouldn’t kick in and the computer wouldn’t sleep. I expected a recent change to have caused this but after backing out the latest program install the problem remained. It was time to brush off some dusty brain cells and remember the command to see what process is keeping the screen saver from kicking in. The following command, when run from an administrator command prompt, shows what process (or processes) is keeping the screen saver or other power saving features from kicking in.
This will display the processes interfering with the power saving features. In my case it was the Synergy process.