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

This did not work for me.  Still having the same issue.

this was not helpfull

This totally worked!

This thread is quickly spiraling out of control, so a Community Moderator has intervened to unmark the “answer” and convert the thread to a discussion. Nevertheless, it’s doubtful that the thread will actually be able to recover at this point. It’s impossible to provide a general “answer” when a thread becomes overcrowded like this – because different people will potentially be reporting different issues, and the answer that works for one person might not work for another.

That being said, there is a very prevalent issue where Windows Defender definition updates fail with error 0x80070643 when a third-party AV product is installed. This appears to be the predominate issue here, and a lot of the turmoil in this thread is due to the fact that the source of this issue is simply not well understood. However, we do now have just a little insight into the underlying error state – and it appears to derive from a disparity in the settings that turn Windows Defender off when a third-party app is installed. This disparity places Defender in an indeterminate state between being switched on and switched off. So the workaround for this error condition is to force Windows Defender to turn off by using the Group Policy switch. We have a very important (but little noticed) thread that confirms the effectiveness of this method here:

http://answers.microsoft.com/en-us/protect/forum/protect\_defender-protect\_updating/windows-defender-conflict-in-windows-10-with-other/36fc885f-d2b7-4ca4-b2c8-c91cd9533a7b

http://www.tenforums.com/tutorials/5918-windows-defender-turn-off-windows-10-a.html

This was also my own experience when I reproduced this bug by enabling Windows Defender in its own registry key. When I subsequently disabled Defender in the Policies key, the update issue was immediately resolved. So it should be clear that although turning Windows Defender off with Group Policy doesn't correct the underlying issue with the registry setting in the Windows Defender key – it does override that setting and fix the update issue.

In the long version of the Group Policy fix, where the third-party AV app is removed and cleaned up before turning off Windows Defender, it’s possible that the underlying error in the Windows Defender registry key is actually being corrected when the third-party AV app is reinstalled. But as I’ve previously explained, this has yet to be confirmed:

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

These two threads are your primary resources for dealing with this specific issue.

GreginMich

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.