Windows Update is conflicting with Windows Defender's auto-update...

I noticed that Windows Update tries to install KB2267602, even though Defender already installed that particular version of the update, resulting in Windows Update throwing an error.

Windows Update output:

Code:

Definition Update for Windows Defender - KB2267602 (Definition 1.249.380.0) - Error 0x80070643

Info from Defender's "Protection updates" page:

Code:

Threat definition version: 1.249.380.0
Version created on: 2:48:19 PM : Friday, July 28, 2017
Last Update: 2:48:19 PM : Friday, July 28, 2017

How do I disable Defender's built-in auto-update so that Windows Update can install it without throwing that error?

I just now tried by setting my connection as metered (to stop most updates), then I checked for updates. It said that a new definition update (1.249.505.0) was available, but when I disabled the metered connection setting to allow it to download, it went all the way through the download and install, reaching 100%, but then I got the 0x80070643 error again. So I went into the Defender app, clicked check for updates, and got this:

Code:

Error code: -2147023293
Error description: Fatal error during installation

How do I fix this? I checked and 0x80070643 in hex is equivalent to -2147023293 in 32-bit signed integer format, so it's the same error code, just in a different format. All the other Windows updates work fine, it's just the KB2267602 updates that throw this error.

I found someone else having the same problem: https://answers.microsoft.com/en-us/...e-6f7b80755cb5. I followed the link on page 9, downloaded and installed the updated definitions manually (1.249.505.0), and checked in the Defender app. It says it's up to date, but Windows Update still tries to download and install the version I just installed, resulting in the above error.