You need to add the DVR server in the Server Manage list, in order to access it. For this purpose, launch the software, press Local Setup and click the Add button below Server Manage. Select 37DVR as server type, enter the IP address of the DVR in the Address field, type a name, enter the port number used on your router to stream videos (usually it is 777) and set a username and password if you want. After that, press the OK button. For further information, check the official user guide.