Here is small working example to start with ... #NoTrayIcon #include <WindowsConstants.au3> #include <Constants.au3> #include <WinAPI.au3> #include <SendMessage.au3> Const $ICON_BIG = 1 Const $ICON_SMALL = 0 Run("C:\WINDOWS\notepad.exe ") WinWait("[CLASS:Notepad]", "", 10) $hWnd = WinGetHandle("[CLASS:Notepad]") If @error Then MsgBox(0, "", "An error occurred when trying to retrieve the window handle.") Exit EndIf $hIcon = _WinAPI_LoadImage(0, "c:\Program Files\Aut