Windows Defender Definition updates download but do not automatically apply

Since 22H2 every day I'll have a defender definition update sitting in Windows Update waiting on me to click the install button. As soon as I do, it installs in seconds. In the past these always automatically installed with no intervention from me. Anyone got any ideas why.

Did you ever get any Windows Update error code for the Defender updates? I can't recall ever getting the infamous 0x80070643 error code with 11, so far. That was common with 10, OTOH.

When automatic updates don't work as they should, you can manually update Defender instead. This ComputerWorld story covers various methods that will do the trick: How to manually update Windows Defender (Jan 2022). HTH, =Ed=

Ed Tittel said:

When automatic updates don't work as they should, you can manually update Defender instead. This ComputerWorld story covers various methods that will do the trick: How to manually update Windows Defender (Jan 2022). HTH, =Ed=

Click to expand...

That story is behind a registration paywall. Unless you care to summarize, it's not solving his problem.

Windows is too smart for it's own good. If it detects a background activity, it might postpone updates to prevent performance issues. You can try to optimize Defender with some settings using DefenderUI - like an hourly updates.

The only registration that's needed is to provide a valid email address. But thanks for pointing that out. The story shows how to jump into Windows Security and run the update from the Windows Security --> Virus & Threat Protection item, like so (Click on protection updates):

From there it goes onto explain that you can use the PowerShell Update-MpSignature command. Finally it provides a link to the MS Download page where you can always find the latest signatures and engine files.
That pretty much sums it up.
Thanks again for observing that those who don't wish to register cannot read those stories. Because CW pays me to write that stuff, I don't see it as an issue. Others may see it differently.
--Ed--

Thanks for the clarity, I was a CW print subscriber back in the days before online help existed.

If I simply go Windows Security > Virus & threat protection updates > Protection updates > Check for updates > Update successful (checkmark in green circle) > Quick scan > Microsoft Defender scan results (pop up notification) No new threats found.

... I thought that I scanned my machine with the latest virus definitions, no?

glasskuter said:

Since 22H2 every day I'll have a defender definition update sitting in Windows Update waiting on me to click the install button. As soon as I do, it installs in seconds. In the past these always automatically installed with no intervention from me. Anyone got any ideas why.

Click to expand...

If Defender automatically scans your device, does it scan with the most recent antivirus definition?

Yes, I believe it will. But I'm enough of a "belt-and-suspenders' guy where security is concerned, that I run the manual update first anyway. Go figure!
Thanks for asking,
--Ed--

Yeah, I seem to remember reading a MS source that says Defender updates before scanning. So, that's how it's supposed to be.

The question was directed to @glasskuter because she posted that Defender downloaded but did not install the update without her intervention. She could check right after an automatic scan if the automatic scan was using the latest update.