Host names and the Domain Name System (DNS) work together to allow computer users to navigate the Internet with ease. Unfortunately, DNS communication errors may cause problems with host name resolution. Windows 7 can fix many DNS errors automatically, though some may require external support.
What Is DNS?
DNS is a computer acronym which stands for "Domain Name System." When you type in a website name or an Internet protocol (IP) address in a web browser, it is submitted through the DNS service so that your computer can connect to the address specified. The DNS service plays a major part in allowing Internet navigation, since it not only translates website domain names into the binary components which are used to identify them but also directs networking requests from one computer or server to another based on these components. Newly-submitted domain names may take up to one or two days to be properly identified by the DNS system in all parts of the world... this is a process known a "propogation." DNS also makes possible the delivery of email and similar communications, since it directs the messages to the proper website or computer so that they can be delivered.
Host Name Problems
Host names also play a large part in navigating the Internet, as these are the names that are used to identify specific computers or domains within a network. When a website address or other host name request is sent across the Internet, DNS translates the host name to its associated IP address so that the requested computer or server connection can be made. Unfortunately, problems may sometimes appear when host name requests are sent to DNS; communications errors can cause the DNS request to fail, resulting in an error message stating that the browser cannot display the requested information or the host name cannot be resolved. If Windows cannot find the host name using DNS, this generally doesn't indicate a permanent problem. You may be able to fix the error yourself, so long as the problem is localized to your computer or network.
Windows 7 features a built-in network scanning solution that can be launched directly from Internet Explorer. If you have received an error message because Windows cannot find the host name using DNS, click the "Diagnose Connection Problems" button to launch Windows Network Diagnostics. The diagnostics tool will scan your network connection, letting you know if any problem is detected and offering you solutions such as the option to reset your network adapter so that it can correct its DNS configuration.
If you are still unable to resolve a host name through DNS, unplug your modem and router then plug them in again after 30 seconds to reset them as well. If the problem existed within your network hardware, this reset will correct improper configurations that may have interfered with DNS communication. Should you still be unable to connect to a host name after resetting your network adapter and the network hardware, check to see if you can resolve other domain names. It may be that there is simply a problem with the specific computer or server that you are attempting to connect to, so you will have to wait until the problem is resolved on the other end of your connection. If you can't connect to other websites, contact your Internet service provider to inform them that you are experiencing a service outage so that it may be repaired.
Image Credit: Screenshots by J. Edward Casteele