Windows Defender Definitions attempts auto update but fails . . .

Avast Free Antivirus / Premium Security
1

I installed the new version of Avast! (2015.10.2.2215) a few days ago and have almost immediately encountered a problem. Windows Update attempts to install a Windows Defender definition file (KB2267602) but fails. The error code is 80070005. I’m encountering this issue with two similarly configured Windows 8.1 laptops. Windows Defender is disabled, and can’t be re-enabled manually – I believe because Avast!, as a third-party antivirus program, disables it automatically. Windows Update doesn’t eliminate the file from the list of pending “important” updates.

I didn’t encounter this issue before the recent Avast! program update, which is why I associate the two events. Of course, MS might have misclassified the file, or this problem might be caused by some other conflict (for instance, with Comodo firewall). But Avast! is my number one suspect at the moment.

Has anyone else encountered this issue? Thanks.

2

According to this it could be malware www.support.microsoft.com/en-us/kb/968003

So i recomend to follow the sticky post at top in Viruses and Worms forum section Logs to assist in cleaning malware

3

Thanks. I had seen that, but I don’t think that is the solution. Here is someone else who just recently encountered the exact same issue and associates it with the Avast! update: http://www.eightforums.com/windows-updates-activation/63582-kb2267602-fails-install.html . The solution here also didn’t work for me, however.

4

Then attach the requested logs and we can rule out another option if nothing is found

5

I had the same problem with the same error code. The only way I could get it to install was to uninstall Avast. (disabling it did not help)

6

Sounds like avast corrupted windows defender. Obviously if you cant enable it manually there is something wrong with it hence the definition will not install either.

Uninstall avast and see if it returns to normal or alternatively go back to a previous image and try again.

7

In windows 8 windows defenders is automatically disabled when you install a third part antivirus you do not have the option to turn it on manually.

As stated above the updates will install if you uninstall Avast, and reinstall after.

8

Thanks, JWA. Uninstalling Avast! worked. I uninstalled Avast!, enabled Windows Defender, installed the definitions file update, disabled Windows Defender manually (from the Administrator option on WD’s Tools tab), and re-installed Avast!. I will be interested to see if I encounter this same problem again, if Windows Update tries again to install a WD’s definitions update.

Pondus, before JWA offered his suggestion, I was preparing to generate and post the log files you had recommended. Of course, malware is/was a possibility, but the reason I was skeptical of that possibility (it was no where near the top of my list) was twofold. First, as I indicated, I encountered this problem simultaneously for the first time on two similarly configured Windows 8.1 laptops – but I don’t use the computers for the same things, so how would they both have acquired the same malware at the same time (unless it was embedded in some major piece of high-reputation software, I suppose)? Second, others on the net have reported the same experience (linked in my previous post). Now JWA has reported his encounter with this issue as well. I hope Avast!'s programming engineers take a look and can track down the source of this behavior. As I indicated in my initial post, it is possible that it relates to something MS did differently when pushing out the recent WD’s definition file update through Windows Update.

I love Avast! despite one or two inevitable hiccups over the years. Nothing is perfect, so perfection is not an option. But Avast! is great.

9

That update was installed on my Win. 8.1 computer on March 7.

10

I am having the same problem here:

Avast has completely disabled Windows Defender, nothing will enable it (neither going to “Services”, nor command line, nor the Windows Defender UI, nothing) which means it can’t update itself, which means I have a 150MB file trying to download and install itself via Windows Update everytime a new definition update for Defender is pushed out, which is everyday!

Do I have to uninstall and re-install Avast everytime a new definition update rolls out? (aka everyday)

Anyone has managed to solve this?

PS: For whatever is worth, the Windows Defender service in “Services” is set to automatically start (shouldn’t avast set it to not auto start?) but can’t even be started manually, it fails to do so with a cryptic “signature is not valid”.

11

First you don’t say what your OS is ?
With later OS versions, windows defender is a full anti-virus

With avast installed Windows Defender (WD) should be disabled (depending on OS) windows should disable WD when a 3rd party AV is installed, as has been mentioned in earlier posts (not the other way round). So if it is disabled then it shouldn’t be updating the definitions.

12

Sorry, I forgot to mention I have Windows 8.1 (yes the one where Defender is a full AV).

I didn’t manually disable Defender before running Avast Installation. Avast (probably) didn’t disable it, it just prevents the service from running (probably).

Now, all the controls in the Defender UI are greyed out, no way to get into Defender settings.

Do I need to uninstall Avast, disable Defender and re-install Avast?

How do I disable Defender properly? (aka so Windows Update won’t try to update it or it’s definitions)

13

As I said windows is meant to disable Windows Defender (WD) when another AV is installed, not the AV being installed.

Unfortunately (or fortunately), I don’t use win8.1 nor Windows Defender. On my other system Win7, WD isn’t a full blown AV, but an anti-spyware and I manually disabled it in win7 and it has never tried to update its definitions.

I would have loved to completely uninstall WD, but like win8.1 and later it is a part of windows and you can’t uninstall it.