Winform Splash Screen - VB.NET - Timer

I would suggest using the built in Splash Screen that is provided by Visual Studio:

Go to the "Projects" menu and select "Add Windows Form" and select the Splash Screen template:

Then in the Project's Application settings, select that form to be the Splash screen:

Your start up form should be your login form, not the splash screen form.

Update:

Click on the "View Application Events" button on the last image from your My Project's Application screen and add this code to set the MinimumSplashScreenDisplayTime value:

Imports System.Collections.ObjectModel

Namespace My
  Partial Friend Class MyApplication
    Protected Overrides Function OnInitialize(commandLineArgs As ReadOnlyCollection(Of String)) As Boolean
      Me.MinimumSplashScreenDisplayTime = 5000
      Return MyBase.OnInitialize(commandLineArgs)
    End Function
  End Class
End Namespace

Your splash screen will remain on the screen for 5000 milliseconds, or 5 seconds.

Try adding a Module to your program with a Public Sub Main Method. Set your project Startup options to Sub Main. You can then do something like:

Module Module1
    Dim frmSplash As SplashScreen1
    Dim frmLogin As Login
    Dim frmMain As MainMenu
    Dim splashTimer As Timer

    Public Sub Main()
        splashTimer = New Timer()
        AddHandler splashTimer.Tick, AddressOf TimerTick
        splashTimer.Interval = 5000
        splashTimer.Start()
        frmSplash = New SplashScreen1
        frmSplash.ShowDialog()

        frmLogin = New Login
        Dim result As DialogResult = frmLogin.ShowDialog
        If result <> DialogResult.OK Then
            End
        End If

        frmMain = New MainMenu
        frmMain.ShowDialog()

    End Sub
    Private Sub TimerTick(sender As Object, e As EventArgs)
        splashTimer.Stop()
        frmSplash.Close()
    End Sub
End Module

Project Settings: