Private Sub Button1_Click(ByVal sender As System.Object, _
  ByVal e As System.EventArgs) Handles Button1.Click
 
   ' zuerst die neue Form deklarieren  
   Dim Form2 As New Form2()
 
   ' dann anzeigen
   Form2.Show()
 
   ' Oder:
   Form2.ShowDialog()
 
End Sub