How can I stop a user closing the login script before it completes?

A. It would be possible to modify GINA.DLL and it has been done in the past but there are none available for download at this time.

An alternative is to hide it. This can be done by creating DWORD valueHKEY_USERSConsoleWindowSize and set to 050005 in Hex andHKEY_USERSConsoleWindowPosition set it to 04FF06FF in Hex. Thismakes the Window very small and positions it off the screen.