How To Use A DLL: To use a DLL, first you must load the DLL file itself using LoadLibrary(). After that, you use GetProcAddress() to load the function you want from that DLL. Here's some sample code: #include int STDCALL WinMain (HINSTANCE hInst, HINSTANCE hPrev, LPSTR lpCmd, int nShow) { HINSTANCE DllHandle; //Create an int called MBAFunction that's a pointer to a function. //The function which it points to takes the following parameters, in //the following order: HWND, LPCTSTR, LPCTSTR, and UINT. //(These are the parameter types used by the MessageBoxA function, //which we will point to with this pointer.) int (*MBAFunction)(HWND, LPCTSTR, LPCTSTR, UINT); DllHandle = LoadLibrary("user32.dll"); MBAFunction = GetProcAddress(DllHandle, "MessageBoxA"); //MessageBoxA is the ANSI message box function, as opposed to //MessageBoxW, which is the Unicode one. //Now, call the function! MBAFunction(NULL, "Hello, world!", "A DLL-using program!", MB_OK); //It's supposed to be good manners to free the library handle when //you're done. However, in my experience, this always makes the //program crash after it displays the message box, so this is //commented out. //FreeLibrary(DllHandle); return 0; }