If you don’t know your DNS server is valid, you need to find out before July 9. The FBI found rogue DNS servers and replaced them with clean, safe DNS servers to protect the public. These safe, clean servers will be turned off on July 9, 2012. If your computer was compromised to use the rogue servers, it will stop resolving DNS queries on July 9 when the clean servers are turned off. The FBI has provided full technical details at http://www.fbi.gov/news/stories/2011/november/malware_110911/DNS-changer-malware.pdf...(read more)