If you cannot connect to the internet and have this problem "DNS isn't responding", this is a problem in your isp provider. Try following the solutions on Windows 7 computer or any version of windows you can do similarly.
Quick Solution - DNS not responding
On your windows 7 desktop right-click on the network icon and click Open Network and Sharing Center.
Click on Change adapter settings.
Right-click on the network card you are using for your internet connection.
On LAN properties, choose IPV4 and click on properties.
Set up DNS server using google public dns server ip adress.
Click on OK and Disable your LAN and Enable it again.
Restart your computer to take effect and browse any websites if this dns not reponding is now fix. If there is no error on dns not responding, then this solution works. Thanks.