Once you can come across a problem when you are actually connected to internet, but no webpages can be downloaded. The source of the problem can be in DNS server. To change DNS server follow these instruction:
1. Go the Control Panel.
2. Click Network and Internet, then Network and Sharing Center, then Manage network connections.
3. Select the connection for which you want to configure Google Public DNS. For example:
4. To change the settings for an Ethernet connection, right-click Local Area Connection, and click Properties.
5. To change the settings for a wireless connection, right-click Wireless Network Connection, and click Properties.
6. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
7. Select the Networking tab. Under This connection uses the following items, click Internet Protocol Version 4 (TCP/IPv4), and then click Properties.
8. Click Advanced and select the DNS tab. If there are any DNS server IP addresses listed there, write them down for future reference, and remove them from this window.
9. Click OK.
10. Select Use the following DNS server addresses. If there are any IP addresses listed in the Preferred DNS server or Alternate DNS server, write them down for future reference.
11. Replace those addresses with the IP addresses of the Google DNS servers: 184.108.40.206 and 220.127.116.11.
12. Restart the connection you selected in step 3.