Definition Update for Windows Defender - KB2267602 (Definition 1.213.5087.0) - Error 0x80070643

As this was a rather new installation with few apps/programs installed, I chose to reset the whole computer, just keeping my files. It solved the problem. Reinsallation of the lost programes was easy and quick. 

Thanks, Arvid GunderBørretzen. It’s good to know that resetting the PC fixes the problem. I did a test installation of a Norton trial about a month ago and Windows Defender was correctly disabled with no Windows Defender update issues. So your experience reinforces the idea that this issue isn’t something that happens consistently – there’s some unidentified factor with the PCs (or with the methods used by their operators) in cases where the installation/reinstallation isn’t successfully disabling Defender.

Since identifying that factor might not be the simple chore that some people seem to think it ought to be, I’m still encouraging people to try the simple workaround of disabling Windows Defender with Group Policy – and anyone who really wants to be helpful here can do the long fix (uninstall with the removal tool, disable with Group Policy, reinstall):

http://answers.microsoft.com/en-us/protect/forum/protect\_defender-protect\_updating/definition-update-for-windows-defender-fails-over/02927e61-14b5-4255-b4d7-e8c93114fdd0

Then run this registry query (copy, paste, and enter this line at the command prompt):

reg query "hklm\software\microsoft\windows defender" /v DisableAntispyware

And report the return value here. This will tell us whether or not the long fix is really setting the proper registry values in the Windows Defender key, or if the Group Policy switch is merely overriding the incorrect values and masking the underlying issue (whether this is actually a fix, or just a workaround).

GreginMich

Taking a clue from the reply of Readhead\_Sailor in this thread:

http://answers.microsoft.com/en-us/protect/forum/protect\_defender-protect\_updating/definition-update-for-windows-defender-error/6184a3e1-d60c-4c74-957e-6f7b80755cb5?page=6

I’ve just found some further corroboration for my analysis in these Norton Community threads – so if you folks ever manage to pull out of the tailspin that you’re in, then the information here might prove helpful:

Microsoft Defender Definition Update Failing:

https://community.norton.com/en/forums/microsoft-defender-definition-update-failing

Norton install does not set Defender keys to properly disable:

https://community.norton.com/en/forums/norton-install-does-not-set-defender-keys-properly-disable

Also note that the links provided by Readhead\_Sailor are bad, and should be edited by a moderator.

[Edit for update, 5/23/2016]

Norton users who are experiencing the Windows Defender definition update issue should definitely have a look at the solution brought to us by hughie55 in this Windows discussion thread:

http://answers.microsoft.com/en-us/windows/forum/windows\_10-update/definition-update-for-windows-defender-kb2267602/d4edd314-a438-4ac2-b7a9-dc1c45a1ef62

This procedure appears to be resolving the issue by setting the correct values in the Windows Defender registry key – and thus avoiding the need for any direct editing of the registry.

[Edit for update, 5/30/2016]

So are we making any progess here, people? My apologies to McAfee users – I missed this one on my previous search:

https://community.mcafee.com/thread/89280?start=0&tstart=0

[Edit for update, 6/11/2016]

Short, non-technical explanation for the prospective fix:

Completely disabling your third-party AV app; starting Windows Defender; and then enabling the third-party app (while Window Defender is still turned on) should disable Windows Defender in exactly the same way that reinstalling the third-party app would:

1.)    Completely disable the third-party AV app in its interface.

2.)    Start Windows Defender

3.)    Enable the third-party AV app

So like it or not guys, we now have a potential solution that’s easy as 1-2-3; that completely resolves the issue, and that only takes a minute (more below).

GreginMich

Also note that the links provided by Readhead\_Sailor are bad, and should be edited by a moderator.

@ GreginMich:

Has the "bad" link been taken care of?

Don

Yes sir. All secure and good to go.

Thank you very much.

GreginMich

Yes sir. All secure and good to go.

Thank you very much.

Thanks. David appears to have taken care of it, but we weren't sure.

Don