Mar 16, 2010

AVG Antivirus 9.0.790 Internet / DNS problems in Windows XP

*Update* - March 20th, 2010 - From my testing, it looks like the bug occurred during the upgrade from AVG 9.0.730 to 9.0.790. To get 9.0.790 to work, you'll need to uninstall your nonworking AVG, reboot, and download AVG 9.0.790, and install by choosing Custom, and uncheck everything. This should get you AVG back up and running again.

*Update* - March 17th, 2010 - Temporary solution is to uninstall AVG 9.0.790 and install an older version of AVG 9.0.730--this works fine with Zonealarm installed. Windows 7 machines do not seem to be affected by this bug.


As of March 14th, at two different client sites and on my personal computers, I've run into DNS problems when trying to access the internet after updating AVG Antivirus free edition and business edition version 9.0.790 with Zonealarm installed/uninstalled.

This was a challenge to diagnose because at first, I thought it could be a virus, spyware, or trojan, but the DNS problem showed up in a fresh install of Windows XP. The only site I could visit was and handful of other sites.

Possible solutions I went through: adjust the MTU on the router and network adapter, run AVG, Malwarebytes, Spyware doctor, boot into Safe Mode, repair winsock, Windows Update, but these attempts did not fix the problem. Only after uninstalling AVG, was I able to browse the internet freely again. I am still unsure of the root cause of this, but I will update once there is a solution.


1 comment:

  1. Re AVG 9.0.790 internet/XP problems I have exactly the same issue. My short term solution is as above and have uninstalled 790 and reinstalled 730. The problems disappear. It seems a shame to have to unclick all the custom options with 790 as part of the joy of AVG is the email scanner part.