pszModname (PSZ) - input
The file-name extension used for dynamic link libraries is .DLL.
When a request is made to load a module and a fully-qualified path is specified, the system loads that .DLL, if it exists. If a fully-qualified path is not specified, the system checks if the .DLL is already loaded. If it is loaded, that .DLL is the one that is used; otherwise, the system searches the paths in the LIBPATH string in the "CONFIG.SYS" file and uses the first instance of the specified .DLL it finds. If the current directory is not specified in the LIBPATH, the system does not check that directory to see if a different version exists. Consequently, if two processes started from different directories use the same DLL, but different versions of that DLL exist in both directories, the version of the DLL loaded by the first process is the one used by both processes.