Windows Logon

[slinky2000]

I am trying to write a logon program for a booking system that will start before you get the windows logon message It will check first in the database if that user has booked that particular pc and then pass that username and password to the windows network logon. What I don't understand is passing information to the windows logon.

Does anyone know how to do it. I can logoff a user from the system using ExitWindows but I don't know how to bring the program back up again when you get the windows logon screen again.