Verified answer

You need to do exactly what it says, check all the connections down to the service entry to your home and beyond. Is this the first time you have connected the system or just a router upgrade? If it worked before then the problem is somewhere between the router and the internet connection. Unplug everything from router to internet box. Then turn back on. Sometimes the failure is in when they make a "handshake" to get acquainted and miss the coding and do not recognize each other right away. Just unplug and try again. It not time to panic until you do it a couple of times with same result. Then it time to call the provider to send out service to check your connections. We had a problem and the service provider had to send service to replace an outside coax connector.

Make sure you have all cables connected on the right spot first. On your router, you should have 5 slots of the same shape where you can connect the fat looking phone cable. For the connection of the modem (the other box from you provider), you should connect it to the Yellow one out of the 5 slots of your router. That should only be connected there else your modem and router won't talk.

Does your modem handle DHCP? Is your router setup to be on that same network? Do you want you new router to handle all the local DHCP stuff or is it just another device on the local network? It sounds like you dont have the default gateway setup correctly, at first thought. Depending on your setup, it could be multiple things.

Edit the above and put your network config down so we may be able to help with more info.

In your router's home page go for MAC address/clone settings and select option Use computer MAC address then it will be fine .it is because some providers lock MAC address for internet access