Windows Defender not updating as often as it should?

I have two Windows 10 Pro computers, one a desktop and the other a laptop. The desktop computer works well, Windows Defender updates its virus definitions about when I log on in the morning, so always updated for the day. And this is automatic, I don't have to go to Windows Updates to get the latest Windows Defender update. There may or may not be intraday auto updates for Windows Defender virus definitions, but just having it update when I boot up my computer in the morning is very desirable. This is obviously what I want.

The laptop computer, when I look at the virus definition under "Update", I see that it is usually a day or 2 old. It doesn't update at the morning login, and I usually manually update the virus definitions as a result of the lack of auto updating.

So my question is obviously how do I get the laptop to update Windows Defender virus definitions automatically as often as my desktop. Both have the Anniversary Update, and I'm not aware of any differences in their Windows Update configurations.

Thanks.

1 of 2 days behind doesn't seem a cause for concern. Anyway, as I suspect you want to find out the cause, did you try the manual update button inside WD to see what happens? I had one laptop failing on me when trying to update WD through Windows Update. I think I had to completely remove installed definitions and redownload them again. I copied these commands from someone on this same forum:

"%PROGRAMFILES%\Windows Defender\MPCMDRUN.exe" -RemoveDefinitions -All
pause
"%PROGRAMFILES%\Windows Defender\MPCMDRUN.exe" -SignatureUpdate
pause

Thanks...the manual update button in Windows Defender on the laptop works just fine. I'll try the manual removal thing and see if that helps.

Hi there

It should only update as often as it perceives threats on that particular PC

I'm sure most PC's don't need to have a database containing definitions of the entire planets possible Viruses.

Intelligent updating makes far more sense -- for example if I merely had Windows, with Nothing else installed (not even office) and rarely used the Internet I really wouldn't need a huge amount of Windows Defender updates.

I'm not sure exactly how it works but I'm sure there must be some sensible algorithm in it to decide what's best for the particular computer WD is running on.

One size fits all would IMO be grossly overkill.

Cheers
jimbo

TairikuOkami said:

Lets us know how it goes. WD should update every 2 hours, so maybe the task is damaged after Windows update.

Definitions are updated every few minutes, but with upcoming ATP, it will be every few seconds.

What's New - Microsoft Malware Protection Technologies

You can create a task with system rights to run it, preferable every hour or only at startup, if desired.

MpCmdRun.exe -SignatureUpdate - MMPC

​How to start and create basic tasks with Task Scheduler

I used to do that, have a task that updates Defender's virus definitions. That seemed to break somehow after I installed the Anniversary Update on my desktop. It ran out of Scheduled Tasks, and updated the definitions every hour. It seemed that "run whether or not user is logged on" (or something like that) broke, and I had to change it to run under my account instead of "system". At that point, I got a command prompt window slammed onto my desktop every time that it ran, so I killed that. Played with it quite a bit, but couldn't get it to run without having to see it after that. But my desktop is now updating Defender nicely, so I don't feel the need for the scheduled task.

After trying the "remove all virus definitions" thing and then update yesterday, the laptop did update Defender's virus definitions when it was turned on this morning. One occurence doesn't mean that the problem is solved, but I was glad to see that. I'll keep my eye on it and see what happens in the next few days, but good start!

Thanks.

Okay, after doing the suggested "remove all Defender virus definition updates" and "get latest Defender update", Windows Defender is updating properly on the laptop. Don't know what happened, but seems to be fixed.

Thanks!

Glad to know you got it fixed.

Best regards.

One thing to note if you set a 'metered connection', automatic Defender definitions updates will be disabled. You'll get a notification if the updates get too many days out of date - you should manually download them from within Defender, or by checking for Windows updates.