With Mt Lion, Apple introduced a unified notification center application that alerts you to a number of things like email, etc.  Unfortunately, it also alerts you to recommended system updates. All of this is unwanted on lab/classroom computers.

I have found that the best way to stop the notification center is to hide the application were it lives.  To hide things on Mac OS X, just like in unix, rename them to something that starts with a “.”  Therefore, in /System/Library/CoreServices rename  NotificationCenter.app to .NotificationCenter.app

This command may do the trick ….

sudo mv /System/Library/CoreServices/NotificationCenter.app /System/Library/CoreServices/.NotificationCenter.app