I'm trying detect when a new message box opened (a modal window) by a specific application. (example the type that shows when you try close notepad with modified but not saved file in it on Windows 10) I'm currently using something like this: Local $hwndPrev While 1 local $hwnd = WinGetHandle("[CLASS:#32770; TITLE:Notepad]") ; file not saved dialog promt If $hwnd And $hwnd <> $hwndPrev Then $hwndPrev = $hwnd ; process popup WinClose($hwnd) EndIf sleep(10) WEnd It works fine, however my script uses 1-2% CPU at all times. I can increase sleep time, but I need to detect new window as soon as possible so it can be closed before appearing on screen for too long. I've tried SHELLHOOK, but it doesn't trigger on this type of windows (modal windows?) #include <WinAPISysWin.au3> OnAutoItExitRegister(OnAutoItExit) Global $hGUI = GUICreate('') GUIRegisterMsg(_WinAPI_RegisterWindowMessage('SHELLHOOK'), WM_SHELLHOOK) _WinAPI_RegisterShellHookWindow($hGUI) While 1 Sleep(1000) WEnd Func WM_SHELLHOOK($hWnd, $iMsg, $wParam, $lParam) #forceref $iMsg if WinGetTitle($lParam) = "Notepad" Then ; process popup WinClose($lParam) EndIf EndFunc ;==>WM_SHELLHOOK Func OnAutoItExit() _WinAPI_DeregisterShellHookWindow($hGUI) EndFunc ;==>OnAutoItExit Is there an event based method to detect modal windows? Thank you.

This should work. #include <WinAPI.au3> #include <WinAPISys.au3> #include <WindowsConstants.au3> #include <WinAPI.au3> #include <ScreenCapture.au3> HotKeySet("{ESC}", "_Exit") ; Exit Global $hHookFunc = DllCallbackRegister('_WinEventProc', 'none', 'ptr;uint;hwnd;int;int;uint;uint') Global $hWinHook = _WinAPI_SetWinEventHook($EVENT_OBJECT_CREATE, $EVENT_OBJECT_CREATE, DllCallbackGetPtr($hHookFunc)) While Sleep(30) WEnd Func _Exit() _Free() Exit EndFunc ;==>_Exit Func _Free() If $hWinHook Then _WinAPI_UnhookWinEvent($hWinHook) If $hHookFunc Then DllCallbackFree($hHookFunc) EndFunc ;==>_Free Func _WinEventProc($hHook, $iEvent, $hWnd, $iObjectID, $iChildID, $iEventThread, $imsEventTime) If WinGetTitle($hWnd) = "VCarve Pro" Then ConsoleWrite(WinGetTitle($hWnd) & @CRLF) ConsoleWrite(_WinAPI_GetWindowFileName($hWnd) & @CRLF) EndIf EndFunc ;==>_WinEventProc Saludos