Public Class Form1
    Inherits System.Windows.Forms.Form

Vom Windows Form Designer generierter Code

  Private Sub Form1_Load(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles MyBase.Load
    Label1.Text = "Das Projekt demonstriert, wie zwischen " & _
                  "2 Formen gewechselt werden kann " & _
                  "(hier Form2 und Form3). Schließen Sie " & _
                  "jeweils Form2 bzw. Form3."
    Start.F2.Show()
    Start.F2.Left = Me.Left + Me.Width
    Start.F2.Top = Me.Top
  End Sub
End Class

Public Class Start
  Public Shared F1 As New Form1
  Public Shared F2 As New Form2
  Public Shared F3 As New Form3

  Public Shared Sub Main()
    Application.Run(F1)
  End Sub
End Class

Start.F3.Show()  'bzw. in Form3_Closing Start.F2.Show
Me.Hide()
e.Cancel = True