internet laboratory system

gud day

I need help in my system Internet laboratory system. I only have the logic on how to do it but the problem is that i don't know the codes. I first practice connecting two computers using the winsock of vb and make a simple chat program.
But when i started to think on how to make or my first step in making the system, i stock on it. As the programmer of our team i need first to have idea on how to code and make the program. I assigned my teammates to make first the database so now my task is to familiarize the system.

I need help first on the client, on how to unable the desktop and run the client where the user need first to input the user name and password and when done, they can now use the computer and the timer also will start.

I really need help on this matter..: (.,
sir admin.. help.,
hoping for your support.

best wishes,

chkm8