I would like to code a small pc security application for my work PC.

I usually code for Win95, 98, ME but never really tried to code for a NT based opperating system before. I have, in the past created a application that loaded as a service process from Window's registry, that effectively covered the entire screen, hiding the logon window and preventing "ctrl,alt, and delete" buttun presses...My code however for Win NT 4.0 and I assume for Win 2000, fails to accomplish the above mentioned acheivements.

I would like to code an application that will effectively cover the entire window, preventing the logoin screen to be seen and disables "Ctrl, Alt, and Delete" button presses in a Nt based opperating system. How can this be acheived, or can someone list some useful URL's that explain this procces.