How to restrict Dual login in C# Winforms Application

Hello,

Thanks for reply

The solution you provided can be used when i want the user to login on the terminal where is logged in for the first time.

But my question is if user A logs in on Terminal A, then he tries to login on Terminal B, he would receive a message you already logged in on another terminal. Now when User A logs off from Terminal A and then logs in on Terminal B, he would be able to login on terminal B and not able to login on Terminal A.