In the Windows 7, click the Start button -->the Control Panel --> Network and Internet --> Network and Sharing Center --> On the left hand panel, Click the "Change adapter settings " link --> You will see a list of adapters present on your computer --> Double-click the Local Area Connection --> Select the Internet Protocol Version 4 (TCP/IPv4) and click on properties button --> Check the change the Obtain DNS and fill the DNS server boxes. You can use the following OpenDNS ip:
Typing 220.127.116.11 in the Preferred DNS server boxes.
Typing 18.104.22.168 in the Alternate DNS server boxes.
Then click OK button to apply.