DLL that was not present in memory despite not being formally unloaded

- Raymond Chen is a veteran Microsoft engineer who writes "The Old New Thing" blog, a long-running deep-dive into Windows internals, quirks, and historical design decisions. - This post describes a debugging mystery: a DLL existed on disk but was not present in a process's memory even though it had never been formally unloaded (FreeLibrary was never called). - The explanation involves a subtle Windows loader behavior: when a DLL's DllMain returns FALSE (indicating failure to initialize), the loader automatically and silently removes the DLL from the process's module list, as if it was never loaded — even though LoadLibrary returned a success code in some edge cases. - This is relevant to Windows system programmers and engineers doing crash analysis or forensic memory inspection, who might be confused by a missing module that their code "successfully" loaded.