#NoTrayIcon
#include<GUIConstants.au3>
GUIcreate("Locker-Outer", @DesktopWidth, @DesktopHeight)
GUICtrlCreateLabel("Press Ctrl-Alt-Del to unlock", 0, 0)
GuiSetState(@SW_SHOW)

While 1
BlockInput(1)
$msg = GUIGetMsg()

If WinExists("Windows Task Manager") Then
BlockInput(0)
Winkill("Windows Task Manager")
Exit 0 
EndIf 
If $msg = $GUI_EVENT_CLOSE Then ExitLoop
Wend