Windows 10 defender gets disabled all the time!

PhytoPhyto Posts: 13 Observer

I have the "optional" search enabled for windows defender.

I use Windows 10 Pro, 1909!


After enabling Windows defender second opinion scanner in windows, it gets disabled after a week, a few days or even two weeks. I have this problem now for more than two years, over several windows installations. Other Virusscanners don`t have this problem, and its only happening as long as F-secure is installed. I only used F-secure internet security during those times.

As it just happened again, plz: solve this problem! Its definetively on the site of f-secure!




  • SethuSethu Posts: 720 F-Secure Employee

    Hello @Phyto 


    Typically, When our F-Secure Product goes from Off to On state, Windows automatically disables all Windows defender feature. F-Secure product only reports to Windows that we are providing real-time protection, and Windows turns off these Defender options automatically. F-Secure is not doing that, in fact Microsoft does not allow us to manipulate Defender settings.


    This Security Alert window appears if Periodic scanning option is turned on in Windows Defender. Periodic scanning is an option in Windows Defender that scans your computer periodically for malware. But, F-Secure's more comprehensive features like Automatic Virus protection, Ransomware protection, Browsing Protection, Banking protection loads into memory when Windows starts and provides you zero-day protection against security threats.


    In addition to Real Time Protection, F-Secure runs Quick Scan periodically to scan important system files that viruses often target.

  • PhytoPhyto Posts: 13 Observer

    So do you deactive that feature or not? Since my writing it happened 1x again. As i said, it does not happen with other virus scanners and it is not system related, cause it happens now for more than two years on different systems. If you say that you should not use the second scanner anyway that is fine, but all i want to know is what is disabling this feature, and as far as i know it is somehow f-secure related.

  • SethuSethu Posts: 720 F-Secure Employee

    Hello @Phyto 


    No, F-Secure has no such option as we just reports to Windows that our F-Secure real-time scanning going to enable. Since the "periodic scanning" setting is managed by Windows is unclear from Microsoft documentation that verified by our backend team, but it is clear that it is by design that Windows disables Defender's real-time scanning when another AV is active, for performance reasons. I found this similar thread from MS community for same topic.

  • PhytoPhyto Posts: 13 Observer

    Look, i get what you are saying, still F-Secure somehow disables this function. I tried it out now two times with different systems. As soon as i turn the second opinion scanner function on from microsoft, a week or so later it gets disabled. On both completely different Systems. Only with F-secure. Not with Avira. not with Kaspersky, not with Bitdefender!

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