MajorGeeks published a quick tutorial about changing the maximum processor frequency in Windows 10.
How to Add or Remove 'Maximum processor frequency' in Windows 10
Maximum processor frequency specifies the operating frequency of your CPU's core. Maximum processor frequency is hidden and set to 0 by default, which means your processor runs as fast as allowed. Advanced users can slow down the processor if your computer is running hot or consuming too much power.
How to Add or Remove 'Maximum processor frequency' in Windows 10