I just wasted a full 2 day trying to say solve the same issue.
It turned out that I had some malware on my computer, named SENDORI, which messes up all of your DNS and other Internet browser settings.
It got caught by my AVG free virus can.
But AVG could not remove the threat, apparently.
It got my problem solved when I restarted my computer in safe mode and I uninstalled the SENDORI program from the "uninstall program" window.
?then I run the free program Ccleaner to get rid of the bad registry keys, and then my Internet was working again properly.
?Hope it helps!!