|That is a fairly straight forward proceedure, some things i need to establish|
1) what is the user enter his username eg smith123, incorrectly enters the password 2 times, then switches username to john123 should the counter reset for this user or should it continue to count from the previous? i would assume it will reset the counter?
2) do you know how to connect VB to access? i would use ADODB
now for the logic.
when the application launches you want the login screen to appear above the main window (main application) this is easily done by disabling the main window and enabling the login screen AND setting the login screen to be AlwaysOnTop (google it).
Now i would suggest that the login screen has a dropdown menu for the usernames, this can be pulled from the database so that you have an accurate list of all registered users.
Each time the user selects a username, set counter to 0, when a password is enetered check it if is correct, if yes then login, enable main window, close login screen. if incorrect, counter +1..
counter = 0
do until counter =3
if password = incorrect then
counter = counter + 1
mainwindow.enabled = true
this is a quick pseudo example of the logic, its basically how you will catch the incorrect password attempts and close the app.
Show us what you have done already and we can help you develop it further....... if you have nothing so far i will suggest you do as you will find that people will not help unless you show that you are trying to tackle the problem yourself first.
show us your code.