Are you using the wired or wireless internet connection?
If you haven't done the basic t/s then first do that:
(1) Check for the dynamic IP address and make sure, its not static from ncpa.cpl location
(2) Check for the compatible drivers and make sure in Device Manager there is no yellow or red exclamation mark in front of the drivers
(3) Check for the services.msc and make sure that Wired Auto Config and Wireless Auto Config services are enabled.