When attempting to update Windows Defender a message appears saying that the definitions could not be updated with the information: “Error found: Code 0×80244030″. Reinstalling Windows Defender has not resolved the issue. The computer is running Windows XP.

The error code 0×80244030 is not specific to Windows Defender, but is a general error code provided by Windows Update. When researching this problem it seems that other users have experienced this same problem with Windows Defender, and also the same error when attempting to use Windows Update. However, there are some procedures which may resolve the problem. First, try re-registering the XML components used by Windows Update. These components are used to communicate information about the update process to the Microsoft update servers and if they are not properly registered with the computer this communication may have broken down. To do this, go to the “Start” menu > “Run” and type ?regsvr32 Msxml3.dll? then click OK. A message should appear informing ?DllRegisterServer in Msxml3.dll succeeded?. Click OK to close the message. Repeat this procedure again, executing the following commands:
? regsvr32 Msxml2.dll
? regsvr32 Msxml.dll
Once all three commands have succeeded, try running the Windows Defender update to see whether the problem has been resolved.

Should the problem continue, you may need to download and install the latest update for the Microsoft XML Parser. Visit the Microsoft downloads website (www.microsoft.com/downloads) and search for “Microsoft XML Parser” (without the quotes). My research indicated that you need to install the ?Microsoft XML Parser (MSXML) 3.0 Service Pack 5 (SP5)?. Find this entry in the search results, and then download and install the service pack. Once complete, restart the computer and check whether the problem persists. If the problem is not resolved, you may need to download a more up-to-date service pack. Return to the Microsoft XML Parser downloads search results, and download then install ?Microsoft XML Parser (MSXML) 3.0 Service Pack 7 (SP7)? to see whether this later service pack will fix the issue.

If the problem still persists, try resetting the Internet Explorer preferences. While this may seem strange, since you are seemingly not using Internet Explorer to update Windows Defender, the update process employs Windows Update which uses Internet Explorer. Therefore, corrupt or incorrect Internet Explorer settings may be causing the update process to fail. Open Internet Explorer then go to the “Tools” menu > “Internet Options”. If you are using Internet Explorer 6, select the “General” tab and click “Delete Cookies” then “Delete Files” (tick “Delete all offline content”) and “Clear History”. This will clear most of the saved data within Internet Explorer. To finish the clearing process, click “Settings” and “View Objects”. A window will appear showing the “C:WindowsDownloaded Program Files” folder. Delete any files located in this folder. After you have finished, close the window and click OK to return to the main Internet Options window. Select the “Security” tab and click “Default Level” and then select the “Privacy” tab and click “Default” (if not greyed out). Finally, select the “Advanced” tab and click “Restore Defaults”.

If you are using Internet Explorer 7, follow much the same procedure except on the “General” tab you only need to click “Delete” and then “Delete All” to automatically delete the cookies, files, and history. Additionally, on the “Advanced” tab you need to click the “Restore advanced settings” button. Once this is complete, check whether the problem persists.

If still no luck in resolving the problem, go back into the Internet Options and select the “Advanced” tab. In the Settings list, under the Browsing heading, untick (disable) ?Enable third-party browser extensions?. This will disable any add-ons or toolbars installed into Internet Explorer. Click OK and restart the computer. Check whether the problem continues. In the event that the problem is resolved, it is being caused by a third-party add-on to Internet Explorer. There is an entire troubleshooting procedure just for this problem, so should this be the case then please contact me again for further advice.

However, should the problem still continue then as a last resort we can try re-registering the Windows Update components. Go to the “Start” menu > “Run” and execute the following commands (much like when re-registering the XML components earlier):
? regsvr32 jscript.dll
? regsvr32 wuapi.dll
? regsvr32 wuaueng.dll
After this has completed, try running the Windows Defender updates again. Should you still encounter difficulties, or any error messages appear when attempting to re-register these files, then please contact me again.