Public Function KeyDownDeakt(byval KeyCode As Integer, byval Shift As Integer) _
  as Integer
 
KeyDownDeakt=keycode
 
 If Shift = vbAltMask Then
  If KeyCode = vbKeyF4 Then
   KeyDownDeakt = 0
  End If
 End If
 
End Function

'A L T + F 4   D E A K T I V I E R E N'
Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
 
KeyCode =KeyDownDeakt(KeyCode, Shift)
 
End Sub