how to create a file using add on and also to add a registry and also

[roxy]

hi every one

my aim is to create an os with usb mass storage device disabled, so i created a batch file to add a registry with a dword value 3 and then to change the value to 4, but this all to be done silently and also to be embeded into the os, tried with add on maker, but it gives an error message" cannot create file "c:\programm files\virtualltek\add-on maker\exec.exe, access is denied",

is there any other method to create an os with usb disabled during installation of OS itself, and the administrator/system/users should not be able to change the value of the registry

Edited January 12, 2012 by roxy