A module is an executable file or DLL. Each process consists of one or more modules. A merge module is a special kind of Windows Installer database that contains the components needed to install a discrete software bundle. The first module is the executable file. Remember that these module handles are most likely from some other process, so you cannot use them with functions such as GetModuleFileName. Modules are collections of cmdlets that are stored in the path %WINDIR%\System32\WindowsPowerShell\.