You can easily disable power to USB ports in your computer through the Windows Device Manager utility. Turning the power off on these ports can be beneficial for security purposes, for saving power or battery consumption when you are not using these ports, or even when you shut the system down and the ports remain powered.
Click the Windows "Start" button. Select "Control Panel," "Performance and Maintenance" and click on "System." If you use "Classic View" in "Windows Explorer," select "Control Panel" and click on "System."
Select the "Hardware" tab and click on the "Device Manager" button.
Scroll down the list and click on the "+" sign that corresponds to "Universal Serial Bus controllers." All available USB ports display. Right-click on the "USB Root Hub" item and click on "Properties" option from the drop-down menu.
Select the "Power Management" tab, check the box for "Allow the computer to turn off this device to save power" option and click "OK" to confirm.
Perform the same procedure on the "USB 2.0 Hub," if applicable.