Have you ever wondered how effective your PC's power management settings really are? Neuber Software has a neat freeware tool called PCTime that helps you determine just that. It analyzes the Windows event log to show you a visual representation of not just a cumulative run time, but how long your PC has been on, but also exactly when and for how long each time.
I used this to determine that the laptop was never going into sleep mode by itself, which is a problem because laptops aren't designed to run 24/7. Which it was. The cooling fan and heatsink assembly has already been replaced once under warranty, which is long expired. And the failure of it probably means the end of the laptop since it's six years old and those specialized parts impossible to source.
I also used it to check our home media server, which it sometimes on for hours at a time, which is expected when it is serving files or doing backups of the other PCs in the house. But it also appears to be turning on dozens and dozens of times per day, only for a minute or two. Even when there's nobody home or everyone is asleep! One day it ran 24 hours straight, which is puzzling. I've got some troubleshooting to do to solve these problems and thus give my ever-climbing hydro bill a break.