Dim currentAssembly As Assembly = Assembly.GetExecutingAssembly()
 
For Each t As Type In currentAssembly.GetTypes()
  If t.IsSubclassOf(GetType(Form)) Then
    Dim instance As Form = CType(t.GetConstructor(Type.EmptyTypes).Invoke( _
      Nothing), Form)
    Me.ComboBox1.Items.Add(instance.Text)
    instance.Dispose()
  End If
Next

Ralf