Public Class Form1
 
    ' benötigte API-Deklaration
    Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" _
       (ByVal lpClassName As String, ByVal lpWindowName As String) As Integer
 
    ' benötigte API-Deklaration
    Private Declare Auto Function ShowWindow Lib "user32" (ByVal hWnd As _
      IntPtr, ByVal nCmdShow As Integer) As Integer
 
    Dim wHandle As Integer
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
 
        wHandle = FindWindow("Notepad", "Unbenannt - Editor")
        MsgBox(wHandle)
        ShowWindow(wHandle, 0)
    End Sub
 
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button2.Click
        MsgBox(wHandle)
        ShowWindow(wHandle, 1)
    End Sub
End Class

---------------
VB.NET macht Spaß!