Computer locked up, windows security alert

Question

My wifes computer is locked up, IP address used to visit harmful sites

Answer 1

Hi, I'm John! I will help you with this.

What you’re seeing is a scam pop-up, not a real Microsoft message. Microsoft does not lock your computer and ask you to call a phone number.

Do not call the number shown on the screen.

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If you haven't tried anything yet please start by:

Closing browser affected by scam pop-up:

• Press Ctrl + Shift + Esc to open Task Manager.
• Look for your browser (Edge, Chrome, etc.).
• Click it, then choose End Task.

If that doesn’t work:

• Press and hold the Power button for about 10 seconds to force shut down.
• Turn the PC back on after 30 seconds.

After restarting:

• Open your browser.
• If it asks to restore previous tabs, choose No.
• Clear your browser history and cache.

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Run a full antivirus scan on your computer using Windows Security and any third-party antivirus software you have.

Run a full deep scan using a trusted security tool:

• Download and run Microsoft Safety Scanner here: https://learn.microsoft.com/defender-endpoint/safety-scanner-download
• After running the scan, please restart your PC and monitor whether the issue continues.

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I really hope this information is helpful! Let me know if you have any further questions or concerns.

Regards,

John J.D.

Answer 2

The behavior described (computer “locked” with a Windows security or Defender alert, mention of harmful sites, often with a phone number to call) matches a common tech support scam delivered through the web browser, not a legitimate Windows security lock.

To regain control of the computer and close the fake alert:

1. Close the browser that shows the alert
   • Press Ctrl + Alt + Del.
   • Select Task Manager.
   • In Task Manager, find the web browser process (for example, Microsoft Edge, Chrome, or Firefox).
   • Select it and choose End task. Repeat if there are multiple browser entries.
   • This closes the full‑screen “locked” page and any pop‑up audio or warnings.
2. If Task Manager is not available or the browser still won’t close
   • Press Alt + F4 repeatedly while the browser window is active to close it.
   • If that still fails, hold down the power button until the PC turns off, then turn it back on.
3. Clear the browser cache after restart
   • Open the browser again.
   • Clear browsing data/cache so the same page is less likely to reload from history.
   • For Microsoft Edge, follow the guidance in the browser’s settings to clear cached data.
4. Do not call any phone number or give remote access
   • Legitimate Microsoft or Windows security messages do not include a phone number to call.
   • Do not call any number shown on the alert.
   • Do not allow anyone remote access to the PC and do not install software they request.
5. Check for real malware
   • Run a scan with Windows Security (Microsoft Defender Antivirus) to ensure there is no actual infection.
   • Optionally, run an additional on‑demand scan such as Microsoft Safety Scanner if concerned about malware.
6. Reduce the chance of future scams
   • Keep Windows and all apps up to date using Windows Update.
   • Use built‑in Windows Security and keep it turned on.
   • Avoid clicking suspicious links or attachments and avoid unsafe or pirated sites.
   • Consider using a modern browser like Microsoft Edge with protections that help block malicious sites.

If no software was installed and no remote access was granted, the incident is typically limited to a scam web page and not a full system compromise.

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References:

• possible virus, computer locked - Microsoft Q&A
• Windows defender scam - Microsoft Q&A
• Microsoft Defender Scam or Do I have a virus on my computer - Microsoft Q&A
• Keep your computer secure at home
• Protect your PC from ransomware
• How to remove the PC Repair virus
• Microsoft Security Advisory 904420

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