no internet access even if wifi connected success

Open network and sharing center, manage wireless networks, choose the connected but no internet access one, right click then select properties to enter properties dialog, open security setup, choose a different encryption type, it's fine to choose a wrong type, because our purpose is just to disable the connection for a minute then reset to right and reconnect. click ok to confirm then wait for the connection down, then reset the encryption type to origin, click ok.