.How can I remove scam Windows Defender security alert from screen?

Michael McCann 25 Reputation points
2025-11-24T17:38:07.5466667+00:00

I was on YouTube via Google and received pop ups regarding a Microsoft Security alert and providing a number to call. I am sure it was a scam; my security system says all is fine. I turned off my computer several times and also hit alt F4, but the alert popups are still on the screen and prevent me from using the web. Help!?

Moved from: Microsoft Security | Microsoft Defender | Microsoft Defender for Office 365

Windows for home | Other | Security and privacy

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Carl-L 20,565 Reputation points Microsoft External Staff Moderator
2025-11-27T04:18:17.3633333+00:00

Hello Michael McCann,

Welcome to Microsoft Q&A forum. It's my pleasure to help you today.

I understand your concern about the pop up you see and why you want to remove it. You are correct, this is a scam. While it does look like legitimate Windows Defender alert, genuine alerts won't ask you to call any number to resolve this.

Aside from what the other has said, if you still see the pop up after clearing the cache and cookies, please consider reset the browser settings. You can do it directly from the browser settings or you can go to Settings > Apps > Installed apps, select your browser and go to Advanced Settings > Reset.

Also, aside from the Windows Defender scanning. You should also scrim around the file and folder to see if there are anything suspicious. The popup might come from an adware that is installed in your computer from a website.

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  1. AI answer

    2025-11-24T17:38:15.9266667+00:00

    To remove scam Windows Defender security alerts that appear as pop-ups on your screen, follow these steps:

    1. Do Not Call the Number: If the pop-up provides a phone number, do not call it. This is a common tactic used by scammers.
    2. Close the Browser: Try closing the browser completely. If the pop-ups persist, you may need to force close the browser application through the Task Manager:
      • Press Ctrl + Shift + Esc to open Task Manager.
      • Find your browser in the list, select it, and click on End Task.
    3. Clear Browser Cache: After closing the browser, reopen it and clear your cache and cookies:
      • For Chrome: Go to Settings > Privacy and security > Clear browsing data. Select the time range and check the boxes for cookies and cached images/files.
      • For Edge: Go to Settings > Privacy, search, and services > Clear browsing data.
    4. Run a Full Scan: Use Microsoft Defender Antivirus to run a full scan of your system to ensure that no malware has been installed:
      • Open Windows Security, go to Virus & threat protection, and select Scan options. Choose Full scan and click Scan now.
    5. Reset Your Browser: If the pop-ups continue, consider resetting your browser settings to default. This can help remove any unwanted extensions or settings that may have been changed by the scam pop-up.
    6. Use Microsoft Edge: If you are not already using it, consider switching to Microsoft Edge, which has built-in protections against known scam sites and pop-ups.
    7. Stay Informed: Be cautious about unsolicited messages and always verify the source before taking any action. Microsoft does not send unsolicited emails or make unsolicited phone calls to request personal information.

    If you suspect that you have been affected by a tech support scam, you can report it to Microsoft and take additional security measures as needed.

    AI-generated content may be incorrect. Read our transparency notes for more information.

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  2. JC 8,235 Reputation points Independent Advisor
    2025-11-24T19:59:32.2333333+00:00

    Hello,

    If these scam notifications are web based they’re likely coming from your browser, go to settings and search “notifications”, and remove all notifications coming from websites.

    Hope this helps,

    JC

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  3. don moore 0 Reputation points
    2026-08-14T14:48:07.3+00:00

    My wife's pc locked up with this fake Microsoft Defender Security Alert and a phone number to call. Scary audio notice as well running in a loop and warning not to shut down. Normal windows were all covered by the full screen pop-up and the general hot keys including Windows key were disabled.

    I called from a unrelated phone and the guy with an accent pretended to be with the Microsoft Defender support team but could give no way to verify that he really was working for Microsoft. He wanted to get a support session started which would take remote access to everything on the PC so I refused and he hung up.

    CTRL-ALT-DEL to see options, and Task Manager worked so I could see this was running within the Edge Browser. Force that task out and the mess on screen and sound stopped --- It is an attack exploiting defects in the Microsoft Edge browser. For confirmation the Defender quick and full scans did not find any issues.

    SUGGGESTION -- pop-ups and alerts are part of some valid web sites, but must have firm boundaries as to how much they can do other than open a text only sub-window.

    Switched default browser to Chrome and no further issues (at least for now). As noted elsewhere it is always suspicious when any pop-up says to call a phone number or you will loose your system or your data.

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