use the included ether net cable(its blue in color) connect it to your modem/router and tool, and perform the system registration on the tools itself 

 Had same issue and found answer here. Download PC suite from this website. Install it and follow directions, you will have to use ths USB SD card adapter to connect the SD card to your pc. Have the serial number of your device handy. When the SD card is updated to the new software, put it back in your DS708 and follow instructions. Afte that you can update online via the wireless features  in the DS708.