Your processor polls your USB ports once every millisecond. It keeps doing this, even if you aren’t going to attach any USB devices. You can increase the polling interval—essentially by enabling “USB idling”—thus allowing some processors to enter power-saving mode.
Navigate to:
HLM\System\CurrentControlSet\Control\Class\{36FC9E60-
C465-11CF-8056-444553540000}\0000
Create a new DWORD value called IdleEnable and set it to 1 to enable USB idling, thus increasing the polling interval. Restart Windows for the change to take effect.
