Option Explicit
 
Private Sub Form_Load()
  With Picture1
 
    ' Picturebox unsichtbar machen
    Call ShowWindow(.hWnd, SW_HIDE)
 
    ' Picturebox auf den Desktop setzen
    Call SetParent(.hWnd, GetDesktopWindow)
 
    ' Taskbar-Eintrag entfernen
    Call SetWindowLong(.hWnd, GWL_EXSTYLE, WS_EX_TOOLWINDOW)
 
    ' Picturebox in die rechte obere Bildschirmecke setzen
    .Top = 0
    .Left = Screen.Width - .Width
 
    ' Picturebox sichtbar machen
    Call ShowWindow(.hWnd, SW_SHOW)
  End With
 
End Sub
 
Private Sub Form_Unload(Cancel As Integer)
  ' sicher is sicher - manchmal stürzt VB ab,
  ' wenn der Original-Besitzer nicht wiederhergestellt wird
  Call SetParent(Picture1.hWnd, hWnd)
  Set Form1 = Nothing
End Sub
 
' ------------ nur zu Testzwecken ------------
' ein Klick in die Picturebox beendet das Prog
Private Sub Picture1_Click()
  Unload Me
End Sub

Option Explicit
 
' USER32
Public Declare Function SetParent Lib "user32.dll" (ByVal hWndChild As Long, _
  ByVal hWndNewParent As Long) As Long
 
Public Declare Function GetDesktopWindow Lib "user32.dll" () As Long
 
Public Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" ( _
  ByVal hWnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
 
Public Declare Function ShowWindow Lib "user32" (ByVal hWnd As Long, _
  ByVal nCmdShow As Long) As Long
 
' CONST
Public Const SW_HIDE = 0
Public Const SW_SHOW = 5
Public Const GWL_EXSTYLE = (-20)
Public Const WS_EX_TOOLWINDOW = &H80&
 
Sub Main()
  Load Form1
End Sub

Viel Spass,
R@lf