From the manual...

Quote:


By default, to prevent users from inadvertently interrupting a script, KiXtart automatically disables the ctrl+c/break keys, disables the Close command in the System menu of the current command-prompt window, and hides the Please wait while your logon script executes message box on Windows 9x.

In a multi-tasking environment such as Windows NT, you cannot fully prevent users from interrupting a program. (They can end programs by using the Task List, for example.) As an additional protection, on computers running Windows NT or Windows 2000 only, when BREAK is OFF (the default) KiXtart also installs a special event handler for the current console. The effect of this handler is that whenever a user forcibly terminates KiXtart, the user is automatically logged off. This means that you must be careful when testing scripts.




To prevent logging off while testing scripts, most of us use 'Break On.' It becomes such a habit that we include it when posting script samples (and even in production scripts).