|I had this same problem on a computer that I was working on. It turned out to be a root kit. I don't know if this is a new build that you have, but you may want to run TDSSKiller just to check.|
Other then that you may want to make sure that you don't have a software firewall blocking explorer or browsers. Make sure that you are pulling the correct DHCP information from your router.
Make sure that your IPv4 properties are correct.
Make sure that your "Internet Properties" are correct and the LAN settings are correct and not using a blank proxy server.
And reset your DNS ipconfig /flushdns
Let me know if any of this works for you or if you need explanations or procedures.