Windows 10: Windows Defender not running scans

I wonder if anyone can identify why Windows Defender has suddenly, i.e. the last day or two, stopped running scans on my home PC?

The product is up to date:





If I attempt to scan a folder of file, the screen above appears and sometimes the scan will run, but more often no scan is performed and the screen below is displayed:





There seems to be no pattern to this erratic behaviour.

I use MalwareBytes and CCleaner in real-time mode so I wonder if they might be affecting Windows Defender at all. However, if both are switched off the same problem occurs.

I have Windows 10 build OS 17763.18.

:)

 

Defender not Running Regular Scan


I've never understood the need some people feel to set up a scheduled task to run a Defender scan. For the past year the automatic maintenance has run Defender scans for me.

That is, until the Anniversary Upgrade - it broke something and Defender never ran another scan. It finally alerted me that a scan was long overdue. I followed the suggestion on another thread...
Windows Defender No Longer Performs AutoScan
...and the automatic maintenance scans are back to running regularly again.

 

How do I get Windows Defender to run a daily scan?

Hi Bill,

To run the Windows Defender automatically, we suggest that you follow the steps on this link:

Schedule a scan in Windows Defender.

Regards.

 

defender scans

Hi Ian,

Thanks for posting your query on Microsoft Community.

This issue might occur if you have set any task scheduler for Windows Defender.

I suggest you to delete the task for Windows defender and check if it helps.

Follow the below steps:

• 
  Search and open Schedule tasks.
  
• 
  In the left-hand menu, open the Task Scheduler Library, then select
  Microsoft >Windows >Windows Defender.
  
• 
  Double-click Windows Defender Scheduled Scan.
  
• 
  Select the Triggers panel, then select Delete.
  

Hope it helps, reply to us with the status of your issue. We will be happy to assist you.