TL;DR: Diagnosing programs causing insomnia is quite straightforward on Windows. My employer has a policy set for Windows machines which locks each computer automatically after some inactivity. One of my colleagues noticed that if they have recent builds of our product running in the background, this auto-locking does not take effect. I was asked to investigate. The bug itself got pretty low priority, as at first glance the phenomenon does not seem to cause that much trouble. I did not know anyt...