Change your DNS Settings

If you are getting frequent "Website not available" messages or the site is taking much longer to load, its time you change your DNS settings to a Fast and Secure DNS like Google Public DNS or OpenDNS. If you opt for Google DNS than follow these steps-
Changing DNS server settings on Microsoft Windows Vista and Windows 7
[For Windows XP goto your Network connection, right click and select properties, now start following from step 6 below ]

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: LAN or WAN
4. To change the settings for an Ethernet connection, right-click Local Area Connection, and click Properties.
5. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
6. Select the Networking tab. Under This connection uses the following items, click Internet Protocol Version 4 (TCP/IPv4), and then click Properties.
7. 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.
8. Replace those addresses with the IP addresses of the Google DNS servers: 8.8.8.8 and 8.8.4.4.
9. Restart the connection you selected in step 3.
10. Test that your setup is working correctly.

Please also have a look at the following images for better understanding.

Step 3

Step 4

Step 6

Step 7-8

Happy Surfing !