Private Const SWP_NOSIZE As Long = &H1
    Private Const SWP_NOMOVE As Long = &H2
    Private Const HWND_TOPMOST As Long = -1&
    Private Const LWA_ALPHA = &H2
 
    Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal _
      lpClassName As String, _
    ByVal lpWindowName As String) As Integer
 
    Private Declare Function SetLayeredWindowAttributes Lib "user32" (ByVal _
      hWnd As Integer, _
        ByVal crKey As Integer, ByVal bAlpha As Byte, ByVal dwFlags As Integer) _
        As Integer
 
    Private Declare Function SetWindowPos Lib "user32" (ByVal hwnd As Integer, _
        ByVal hWndInsertAfter As Integer, ByVal x As Integer, ByVal y As _
        Integer, _
        ByVal cx As Integer, ByVal cy As Integer, ByVal wFlags As Integer) As _
        Integer
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        Dim H As Integer
        H = FindWindow(vbNullString, "Rechner")
        SetLayeredWindowAttributes(H, 0, 128, LWA_ALPHA) [color=green]'das 
        ' funktioniert nicht
        SetWindowPos(H, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOSIZE Or SWP_NOMOVE) _
          [color=green]'das funktioniert
    End Sub

MfG Radon