1. Disable USB Devices:

Disabling USB ports can be a smart idea to add security to the computer. 

This can be really handy if the computer is on a public place where

 the chances of virus and other malware infection is really high. 

You can easily disable access to USB ports with the following registry hack:

1.  Open the Registry Editor (Start -> Run -> Type regedit and hit Enter)
2. In the registry, navigate to the following key:
   
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\UsbStor
3. In the right-side pane, double-click on “Start”.
4. In the “Value data” field enter 4 and click on “OK”.
5. Close the Registry Editor and reboot.