This article explains how to take control of the CPU fan in a Windows 10 computer. To do this, you will need to get inside your PC case, so wear an anti-static wrist strap. You can also touch something metal, such as your PC case, before and during your investigation. This will ground you and prevent static electricity from shorting out components.

Before you can officially take control of your CPU fan speed, you'll need to make sure the connector allows it:

Turn off your PC and unplug it from the wall outlet.

Remove the left side panel if you are looking from the front. There should be some screws on the back that when removed will pop the panel off.