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How do I reset/repair Windows Defender?

Anonymous
2024-02-17T00:28:03+00:00

About a week ago Windows Defender detected several malicious files inside an ISO file on my system. I didn't even know Windows Defender would scan inside ISO files. Either way, I manually deleted the ISO file from my system. Now my Windows Defender is stuck in a bad state. It still says these malicious files exist, but any attempt to quarantine/remove/allow the file results in "Remediation Incomplete." I have rescanned my system, updated Windows Defender, performed a full scan - nothing I do will get me out of this state. Windows Defender still thinks this malicious file is on my system even though it is gone.

Is there any way to repair Windows Defender? Or clear the history? Or reset it back to factory settings? All the steps online to perform these types of tasks are all ineffective.

I'm running Windows 10 22H2.

Windows for home | Windows 10 | Security and privacy

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  1. Anonymous
    2024-05-25T08:08:38+00:00

    hey your link in 2024 wont work . can you help me?

    5 people found this answer helpful.
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  2. Anonymous
    2024-02-19T02:22:54+00:00

    Hello ,

    Good to see you in Microsoft Community.

    You can repair/reset Windows Security app by the following steps:

    1. Clear the Microsoft Store cache "Win" logo key + "R" to open "Run", type "wsreset.exe", and pressEnter*(this will open a blank "Command Prompt" window, which will close and automatically open the Microsoft Store after about 10 seconds).*
    2. Reset Windows Security "Win" logo key + "Q" to open the search box and type "Security", right-click "Windows Security" at the top of the result list > "App settings" > ”Reset“.

    Also, it's important to note that the Protect history in Windows Security is retained for 2 weeks before the expiration history is automatically cleared, so if you've made sure that your system isn't free of malware, you can safely ignore the prompt. Visit Protection History - Microsoft Support for more details.

    Image

    If anything is unclear, please do not hesitate to let me know.

    Best Regards,

    Mosken_L - MSFT | Microsoft Community Support Specialist

    5 people found this answer helpful.
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  3. _AW_ 67,206 Reputation points Volunteer Moderator
    2024-02-19T03:15:37+00:00

    Hi Brian,

    If Windows Defender continues to alert about the file then its likely that this is a bug, where Windows Defender flags things because of their presence in detection history.

    To resolve the issue use one of these methods:

    1. First boot into safe mode:

    https://support.microsoft.com/en-us/windows/start-your-pc-in-safe-mode-in-windows-92c27cff-db89-8644-1ce4-b3e5e56fe234

    Delete the DetectionHistory folder from:

    C:\ProgramData\Microsoft\Windows Defender\Scans\History\Service\DetectionHistory

    Restart your computer.

    Note: To see the ProgramData folder and subfolders,  make sure you are showing hidden files and folders.

    • Windows 10: In File Explorer, select the View tab > check (tick) Hidden items
    • Windows 11: In File Explorer, select View > Show > check Hidden items
    1. Use the ClearDefenderHistory batch file:

    https://github.com/LesFerch/ClearDefenderHistory

    3 people found this answer helpful.
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  4. Anonymous
    2025-01-15T08:02:45+00:00

    My Defender still does not show Virus- and Threatprotection-link.

    When I´m trying to open it, this window appears:

    1 person found this answer helpful.
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  5. Anonymous
    2024-09-12T14:49:48+00:00

    I was able to complete the first step, but not able to complete the second step. for reset windows security.

    Thoughts?

    1 person found this answer helpful.
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