DNS Lookup Failed is quite common when you are using Google Chrome. This issue commonly arises when the settings are incorrectly configured or the DNS server stops responding.Its always recommended to choose the Best DNS Server For Your Computer.
What does DNS Server Do?
It translates domain names (eg: Pcpedia.blogspot.com) to IP Addresses.
How To Fix?
By Default in most computers DNS server addresses are obtained automatically. You need to change it and use open dns. Its recommended to use Google DNS. i.e 126.96.36.199 and 188.8.131.52
Check out this simple video:
Learn How To Change Dns Server Address on Your Computer: