DLL Missing from Process Memory Even Though It Was Never Formally Unloaded

A recent post on Microsoft’s “The Old New Thing” blog examines an unexpected DLL behavior. The author observed a DLL that was not present in a process’s memory. Investigation showed the DLL had never been formally unloaded by the program. The blog explains how Windows can silently remove a module under certain conditions. It details the loader’s reference‑counting and page‑out mechanisms that can hide a DLL. The article provides sample code to reproduce the scenario for developers. Understanding this behavior helps avoid confusion when debugging memory issues. The post advises on diagnostic steps to verify whether a DLL is truly unloaded.