Option Explicit
 
' alle benötigten API-Deklarationen
Private Declare Function SetWindowPos Lib "user32" _
  (ByVal hwnd As Long, ByVal hWndInsertAfter As Long, _
  ByVal x As Long, ByVal y As Long, ByVal cx As Long, _
  ByVal cy As Long, ByVal wFlags As Long) As Long
 
Private Declare Function GetWindowLong Lib "user32" _
  Alias "GetWindowLongA" (ByVal hwnd As Long, _
  ByVal nIndex As Long) As Long
 
Private Declare Function SetWindowLong Lib "user32" _
  Alias "SetWindowLongA" (ByVal hwnd As Long, _
  ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
 
Private Const SWP_FRAMECHANGED = &H20
Private Const SWP_NOMOVE = &H2
Private Const SWP_NOSIZE = &H1
Private Const SWP_NOZORDER = &H4
Private Const SWP_NOACTIVATE = &H10
Private Const SWP_REFRESH = SWP_NOZORDER Or _
  SWP_NOSIZE Or SWP_NOMOVE Or SWP_NOACTIVATE Or _
  SWP_FRAMECHANGED
 
Private Const GWL_STYLE = (-16)
 
Private Const WS_MAXIMIZEBOX = &H10000
Private Const WS_MINIMIZEBOX = &H20000
 
Private Const HWND_TOPMOST = -1
 
' Minimieren/Maximieren Button einer Form anzeigen
Public Sub MinMaxButton(Form As Form)
  Dim Style As Long
 
  With Form
    Style = GetWindowLong(.hwnd, GWL_STYLE)
    Style = Style Or WS_MINIMIZEBOX Or WS_MAXIMIZEBOX
    SetWindowLong .hwnd, GWL_STYLE, Style
    SetWindowPos .hwnd, 0, 0, 0, 0, 0, SWP_REFRESH
  End With
End Sub
 
' Fenster immer im Vordergrund
Public Sub TopWindow(hwnd As Long)
  SetWindowPos hwnd, HWND_TOPMOST, 0, 0, 0, 0, _
    SWP_NOSIZE + SWP_NOMOVE
End Sub

Private Sub form_load()
Befzurueck.default = True
If mainform.Check2.Enabled = True Then
  ' Fenster immer im Vordergrund anzeigen
  TopWindow Me.hwnd
End If
End Sub

Gehe immer vom Guten Willen Anderer aus!