LPVOID lpMsgBuf;
FormatMessage(
    FORMAT_MESSAGE_ALLOCATE_BUFFER |
    FORMAT_MESSAGE_FROM_SYSTEM |
    FORMAT_MESSAGE_IGNORE_INSERTS,
    NULL,
    GetLastError(),
    0,
    (LPTSTR) &lpMsgBuf,
    0,
    NULL
);
MessageBox(NULL, (LPCTSTR)lpMsgBuf, TEXT("Error"), MB_OK | MB_ICONERROR);
LocalFree(lpMsgBuf);