Extremely strange system kill (Bad Avast Update)

Hi folks,

I have my PC, my fiancees laptop and PC, and my mums PC running the same software. It has been running the software for a long time but today every single machine fails to start into Windows, and begins automatic repair but cannot repair anything in the end. I booted into safe mode tried ticking launch services only on MSConfig, restarted but no luck. I disabled Comodo and Avast restarted and managed to get back into Windows, and uninstalled Avast.

I then ticked Comodo to renable it and restarted the PC and that loaded up no problem, which tells me something has gone wrong with Avast. Last night I did have a strange firewall alert for Avast but I accepted it because I thought it would be trusted.

The alert I got was a connection request for:

C:\Program Files\AVAST Software\Avast\Setup\2dc10cdb-b87a-4327-8a36-0358ccb8a9f9.exe

Not saying it could be that but I have never had anything like this ever! Especially the way it managed to stop 4 windows machines booting into Windows. I checked Avast Forums, Comodo Forums, tried searching Google for the error for the last 24 hours to see if anyone else had the same issues. Never did find anything though. Really strange.

Edit.

Fixed 2 PC's so far luckily. Even when using MSConfig and selecting to startup absolutely no startup items, it goes in a reboot loop. Comodo won't let me uninstall in safe mode, however Avast does and as soon as Avast was uninstalled the system booted to windows fine.

Edit:

Found the forum post on Avast reporting this:

http://forum.avast.com/index.php?topic=128242.0

Edited by deleted (Thu 27-Jun-13 14:12:13)

If they are Win7 machines you could try this fix: http://support.microsoft.com/kb/2839011

After I uninstalled security update 2823324 the Win7 machine was fine

Hi 4,

No I don't think it's that, it seems to be an issue with Avast. It says on that page "Microsoft has released security update 2840149. This security update resolves the issue that was introduced by security update 2823324" and I have all recent updates so that would have been hotfixed by now.

Unfortunately the later update didn't resolve the issue for me so I had to uninstall the original 2823324 update that was still causing problems with start-up.

What I did first was to do a system restore to the point before the "bad" update and that fixed the start-up issue. Then ran the updates again, thinking that perhaps it was initially a corrupt installation, but the problem returned.

Secondly I disabled AV on start-up and the machine booted normally. It seems that the mere presence of the bad update on the Win7 machine was causing problems with the AV software and the OS.

Certainly I'm not discounting that it may be your AV program alone that is causing problems but it might be worth uninstalling update 2823324 just to check that it isn't causing issues...

Edited by 4M2 (Thu 27-Jun-13 15:29:00)

No was worth a try certainly thanks. Avast confirmed it was a fault issued to the AV to be compatible with Windows 8.1 preview.