Are you afraid that a virus may enter your computer through USB.......
Do you want to block USB in your computer??
If you want there is a way......
All you can do is,
Type "regedit" in Run box. Then expand to"Hkey_Local_Machine/System/
search for Start in the right side.. Double click it and then change the value 0000000(3) to 4 and then restart your computer....
