Do you want to block any pen or Thumb drive from opening in your system's USB Port?

Let's Disable the USB Ports

FIRST OF ALL

GO TO --> START --> RUN

TYPE REGEDIT

LOOK FOR THE KEY :
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USBSTOR

FIND THE KEY THERE CALLED :-
"Start"

DOUBLE CLICK ON IT.

CHANGE THE VALUE DATA 3 --> 4

WHERE ITS BASE IS HEXADECIMAL

YOU HAVE DONE IT
NOW CLOSE THE REGISTRY AND YOU'LL SEE THE RESULT.
YOUR PC'S ALL USB PORTS ARE DISABLED

TO RE-ENABLE/UNBLOCK USB PORTS JUST CHANGE THE VALUE DATA AGAIN 4 --> 3
NOW YOUR PC'S ALL USB PORTS ARE RE-ENABLED.