USB access is something that can affect your computer in a variety of ways. Whether you’re protecting your computer against viruses or malware, or you don’t want anybody to have the ability to copy files onto a USB memory stick, you will need to restrict the access to the USB ports on your system. Setting this up will give your computer the security it needs and keep your data safe.

• Click “Start” and select “Run.”

• Type “regedit” into the box and press “Enter.”

• Look for “HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\UsbStor.”

• Select the “USBSTOR” entry.

• Right-click on the “Start” file on the right and select “Modify.” Change the value to “4” to deny access to the USB ports.
• To enable it , just turn back value  to “3”.

You can speedup the process by creating desktop shortcut of this procedure. Learn from here: Create shortcut to modify registry files

Note: You need administrator privileges for this.