Not fully sure what u mean. only thing i can think of is when they use sysprep and a form of autoinstaller. most manufacturers make restoration disks - i posted these links sometime back they allow u to do what the manuf do.
hope its what ur after.
http://unattended.msfn.org/
http://www.msfn.org/board/index.php?showtopic=31886
http://www.nliteos.com/