How To disable USB port in windows XP ,Windows vista and 2000.

Step 1st: 
Click Start
then click on Run.
or
press win key + R

step 2nd:  
One box prompted,
then type regedit in that box , and then click OK


Step 3rd:
Find and Locate the following registry key:

HKEY_LOCAL_MACHINE
>SYSTEM
>CurrentControlSet
>Services
>USBSTOR

Step 4th:


In the right side, you have to find Start then double-click on Start.




Step 5th:
In the Start Value data box, type 4
click Hexadecimal (if it is not already selected), and then click OK
and now quit Registry Editor.