windows 10 - CPU usage goes up significantly when computer's screensaver is activated (black screen) - how to identify the source?

My laptop's fan becomes significantly louder when the screensaver (black screen) turns on after a period of inactivity. Once I press any button to activate the laptop, CPU usage goes from 60% to near 0%.

How do I learn what program/process is so active when I'm not at the keyboard?

My OS is Windows 10

Answer

There are several Microsoft-created tools that will help you with this. They offer different user interfaces and abilities, so give them each a try and see if they'll work for you.

PerfMon https://docs.microsoft.com/en-us/sysinternals/downloads/procmon

ProcessMonitor https://docs.microsoft.com/en-us/sysinternals/downloads/procmon

ProcessExplorer https://docs.microsoft.com/en-us/sysinternals/downloads/process-explorer