How to re-install (bring back) Windows Defender?

Amin2234 146 Reputation points


I have third party antivirus installed on my device now I removed that software.
Now I want to have Windows Defender antivirus back to my system. How?

I don't see it in system tray. I can search and open it when I search it in Settings but it does not appear in my system try to make sure it is running and working.
In my "Services" I see only "Windows Defender Firewall" => running (but I suppose there must be another service "Windows Defender")

Windows 10 Security
Windows 10 Security
Windows 10: A Microsoft operating system that runs on personal computers and tablets.Security: The precautions taken to guard against crime, attack, sabotage, espionage, or another threat.
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  1. Docs 13,091 Reputation points

    Microsoft had changed the name from Windows defender to Microsoft defender.

    To make sure that the antivirus software is on or to turn it on after removing third party software see this link:

    Please remember to vote and to mark the replies as answers if they help.

    On the bottom of each post there is:

    Propose as answer = answered the question

    On the left side of each post: Vote = a helpful post

    1 person found this answer helpful.

  2. Leon Laude 85,136 Reputation points

    Hi @Amin2234 ,

    As far as I know if you uninstall your third-party antivirus software, Windows Defender should automatically become enabled (might require a restart though).

    Here's also some information:
    Microsoft Defender Antivirus compatibility with other security products


    If the reply was helpful please don't forget to upvote and/or accept as answer, thank you!

    Best regards,

  3. Limitless Technology 37,611 Reputation points

    Hello Amin,

    Windows Security is built-in to Windows 10 and includes an anti-virus program called Microsoft Defender Antivirus. If you have another antivirus app installed and turned on, Microsoft Defender Antivirus will turn off automatically. If you uninstall the other app, Microsoft Defender Antivirus will turn back on automatically.

    To customize how your device is protected with these Windows Security features select Start > Settings > Update & Security > Windows Security

    You canTurn Microsoft Defender Antivirus real-time protection on or off by following the below step,

    1.Select Start > Settings > Update & Security > Windows Security and then Virus & threat protection > Manage settings. (In previous versions of Windows 10, select Virus & threat protection > Virus & threat protection settings.)
    Open Windows Security settings

    1. Switch the Real-time protection setting to On/Off and choose Yes to verify.

    To Get to know more about Windows Defender antivirus click the below link,

    Hope this answers all your queries, if not please do repost back.
    If an Answer is helpful, please click "Accept Answer" and upvote it : )

  4. Vignesh Devendran 1 Reputation point

    Please try installing Windows Defender Antivirus through this link - details.aspx. Try running it as Administrator.