I have a task of bank program .
At the begining of the program it will requst from me to enter the user name and password
I want the password to appear like ****
I want your help ,I searched about it but I didn't find how

If you are using visual studio, you select the appropriate textbox and under PasswordChar property of the password text box chagne the value to '*'. Hope this helps

my program run on console
how can i do this on console screen

You could try this:

Console.ReadKey(true);
Console.Write("*");

Hope that helps!