This is because you have installed DNS server on the server.
First, you need to confirm whether the DNS server you've installed is actually required.
1) If the answer is yes, you need to disable the DNS proxy in CCProxy: Open the management interface of CCProxy-> "Settings" -> uncheck "DNS".
2) Or you need to stop the DNS server you've installed. Cases such as this happens most frequently in Win2000 because the DNS server is installed automatically. To stop the DNS in Win2000, go to: "Control Panel"-> " Management Tool"-> "Service" -> "DNS Server"-> Change " Startup Type" to " Manual", press button "Stop".