DECLARE INTEGER GetDesktopWindow IN WIN32API DECLARE INTEGER LockWindowUpdate IN WIN32API INTEGER lnHandle hWin = GetDeskTopWindow() LockWindowUpdate(hWin) *COMPILE 123.prg REPORT FORM x TO PRINT LockWindowUpdate(0)You can use this "hide" the output window, but you still can't use this in a .DLL as it's still "there" as UI and won't work in a .DLL.