FreeLibrary and AfxFreeLibrary
Processes that explicitly link to a DLL call the FreeLibrary function when the DLL module is no longer needed. This function decrements the module's reference count and, if the reference count is zero, unmaps it from the address space of the process.
In an MFC application, use AfxFreeLibrary instead of FreeLibrary to unload an extension DLL. The interface (function prototype) for AfxFreeLibrary is the same as FreeLibrary.