This is DNS configuration issue. Your are surely connected to internet but your system does not know how to resolve www.google.com
to its corresponding IP address.
If you know the correct DNS of your ISP, add it to /etc/resolv.conf
file. Open the file in your favorite text editor, and add the following line
If you are not sure or you do not know the IP address of your ISP, you should contact them. Till the time, you can add open DNS