Our ISP (Internet Service Provider) provide their DNS which are located at router. Sometimes DNS server of ISP is very slow then it takes so much time to find out the web address and open the website. To solve this problem you can replace your ISP’s DNS service with Google Public DNS by changing the settings of the network connection.
1) Go to Start -> Control Panel
2) Click on Network Connections in Control Panel
3) Right click on Local Area Connection and then click on Properties
4) Select Internet Protocol (TCP/IP) and then click on properties
5) Select Use the following DNS server addresses in filed Preferred DNS server type 220.127.116.11 and in Alternate DNS server type 18.104.22.168