Occasionally when surfing the Web via Microsoft's Internet Explorer browser you may receive a "DNS Not Found" error message. In most cases, DNS issues can be fixed by accessing the browser's options and correcting its settings. In some cases, you can also fix DNS errors using a command prompt input.
Using IE Settings
Open your Internet Explorer browser. It doesn't matter what page your browser opens to as long as it is open.
Click on the "Tools" option at the top of your Internet Explorer screen. Next, click on "Internet Options," followed by "Security Tab." In the Security Tab, click on the "Custom Level" tab located at the bottom of the screen.
Check the "Medium" security level drop down box once on the "Custom Level" screen. You will also need to browse through the options, find the setting "Access Data Across Domains" and put a check in that box to enable the feature. Finally choose the "Apply" option and the exist the program.
Close and reopen your Internet Explorer browser and try to navigate to a website. You should now be able to load pages. If it is still unable to load, try restarting your computer, as some changes don't always take effect immediately upon applying them.
Using MS DOS Prompt
Click on the Windows "Start" button, followed by the "Run" option. You should now see a Run box. In that box, type "CMD" (without the quotation marks). MS DOS will be launched.
Type the following message into your MS DOS window, "netsh winsock reset catalog" (without the quotation marks), and then press "Enter." Next, type in "netsh int IP reset reset.log" (again, without quotes) and press "Enter." Finally, type "Exit" and then hit "Enter," or simply close your MS DOS window.
Go to the "Start" button and click on the "Shut Down" option. Choose "Restart" and allow your computer to restart. You should now be able to launch Internet Explorer and use it as you normally would.
This has been tested with IE 7 and higher versions.
Some sites recommend disabling your firewall; while this will fix DNS errors in some cases it also puts your computer at risk and is not recommended by most security professionals.