written by: Donna Buenaventura•edited by: Bill Fulks•updated: 9/30/2010
Updating Windows or checking for available updates for Windows is an important task in maintaining the computer. If you are receiving a DNS error in loading Windows Update pages or applications, you may need to reset or re-register the Windows Update files. This article tells you how to do that.
slide 1 of 5
Windows Update Website and DNS Error
Access to Windows Updates is important because it can check the important, recommended and optional updates for the system. Downloading updates using other programs may only help if you are familiar with what update is necessary for the currently installed system and Microsoft applications.
Some users may receive a DNS error when loading the Windows Update page or using the Windows Update application in Windows 7. The following section in this article will discuss how to possibly resolve accessing Windows Update.
slide 2 of 5
DNS Error or Internet Connection Error When Using Windows Update
When you try visiting or connecting to the Windows Update website or server, you may receive DNS or Internet connection related errors. The following steps should help you solve the problem. Try each step before connecting to the Windows Update website.
Temporarily disable your antivirus and third-party firewall programs. If you are using an accelerator or download manager, temporary disable it as well.
Verify that your Internet options are not configured to use a proxy server, unless you are actually using a proxy server connection. In Internet Options, click the Connections tab, and the LAN settings button. Uncheck the box for "Use a proxy server for your LAN".
If disabling the firewall did not help, add Windows Update websites in the trusted sites list in Internet Explorer: Open Internet Options, click the Security tab, and then the Trusted sites. Proceed by clicking the Sites button, and then uncheck the box before "Require server verification (https:) for all sites in this zone". In "Add this website to the zone" type http://update.microsoft.com then click Add button. Do the same for http://windowsupdate.microsoft.com. Close Internet options.
If the problem with connecting to Windows Update continues, reset the hosts file in Windows. Download Microsoft Fix it 50267 from http://support.microsoft.com/kb/972034 and run the file to reset the hosts file to default.
Check or update your version of Background Intelligent Transfer Service (BITS) and determine if Windows has the latest version of BITS. See Microsoft KB842773 to determine the current version of BITS.
slide 3 of 5
Windows Update Agent
If any of the above methods did not fix the DNS error in loading Windows Update page or in connecting to the Windows Update server, you may need to update or reset Windows Update Agent.
Determine the version of Windows Update Agent (WUA) by navigating to C:\Windows\System32 folder and the locate wuapi.dll, wuapp.exe, wuauclt.exe or wuaueng.dll. Hover the mouse over any of those files to determine the version number of Windows Update Agent. At the time of this article, the current version of WUA is v7.4.7600.226. If you have an earlier version number, download the new WUA installer from http://support.microsoft.com/kb/949104/
If updating to a new version of WUA did not fix the DNS error or Internet connection when visiting Windows Update, re-register the wups2.dll file in Windows. In the command prompt, type net stop wuauserv then press enter key on the keyboard to stop the Automatic Update service in Windows. Next, type regsvr32 %windir%\system32\wups2.dll in the command prompt and press enter key again. If you are using a 64-bit edition of Windows, type regsvr32 %windir%\syswow64\wups2.dll instead. Start the Automatic Update service by typing net start wuauserv in the command prompt.
slide 4 of 5
Resetting or Registering Windows Update Files
In some cases, resetting Windows Update is necessary:
Download the Microsoft Fix it 50202 from http://support.microsoft.com/kb/971058 to automate the process of resetting Windows Update components. The article by Microsoft contains the manual method of resetting Windows Update files, but you should only use the manual method if you are advanced-user.
If nothing else works, it could be that your computer is infected with some malicious software. Some computer worms, Trojans or other types of malware can block or prevent a computer from visiting antivirus and Microsoft Windows Update servers. In some cases, the malware can add a group policy object or registry entry that will give a false report about the status of the antivirus program.