Problem with internet connection

I am having problems with my internet connection.I used to have internet at both pc and wireless (pc is connected via wire) but the modem broke down.So I just received a new one. Although everything is connected (modem with pc via ethernet cable) and the modem shows that I have and wireless and internet connection, the pc cant read the ethernet cable (its not the ethernets cables fault I have tried many) What should I do?