alright, first of lets check if the cable is working fine. Behind the linksys router you will find four ports that are together and one port that is separte from the other four ports. Connect the cable's one end to the computer and the other end to one of the four ports that are together. Then check for any orange or yellow or red or any kind of light that is glowing or blinking on the port of the router where we have connected the cable (please note, when you are checking for the lights on the port where the cable is connected , make sure that the computer is switched on).In the same way also check whether there are any lights glowing or blinking the port of the computer where the cable is connected.Once again make sure that the router and the computer both are switched on. If the lights are not glowing on any one of the ports either on the computer or on the router then it means that the cable is gone bad (however since the router is brand new , i assume that it's working fine). If the lights are fine then the cable is working fine. Hope this answers to your query. For further issues do let me know ...