| Platform SDK: Internet Protocol Helper | 
The EnableRouter function turns on IP forwarding on the local computer. EnableRouter also increments a reference count that tracks the number of enable-IP-forwarding requests.
DWORD WINAPI EnableRouter(
    HANDLE* pHandle,
    OVERLAPPED* pOverlapped
    );
If the process that calls EnableRouter terminates without calling UnenableRouter, the system will decrement the IP-forwarding reference count as though the process had called UnenableRouter.
If the function succeeds, the return value is ERROR_IO_PENDING.
If the function fails, use FormatMessage to obtain the message string for the returned error.