Well I would start out and verify you have an IP address, subnetmask a gateway and DNS servers defined.
You can get all this by opening a command prompt and type ipconfig /all you can post the output here if you want it to be checked out. Then verify you can reach the gateway ping <gateway ip> If you can ping that, then ping something on the internet ping 8.8.8.8 this is a public DNS server hosted by google. If you can ping that then try and ping a website such as water.com If you can't ping past the gateway then you will need to contact the ISP