Not so long ago I had the same problem: WiFi connects but says
"no Internet access" (the Internet itself is, with him all right). When you unplug the "control center networks and the General dostupom --> change adapter settings --> wireless network"
and re-enabling wifi once connected automatically. Some time after the successful connection(no exclamation mark on the wifi icon in the system tray) in the browser Opera, but in Chrome there(see screenshot).
The computer has 2 systems: ubuntu and windows, the problem only manifests itself on windows. Drayvera tried to reinstall, like it's not them. Tell me, please, does anyone know how to solve this problem?