A browser warning that says your PC is infected and tells you to call a phone number is a scam, not a real Microsoft alert. Do not call, pay, click Allow, or install anything from it. Close the browser, block the site's notification permission if it has one, remove unfamiliar extensions or apps, and run a scan in Windows Security.
Treat the message as a scam if it uses a support phone number, demands urgent payment, asks for gift cards or cryptocurrency, or wants remote control of the PC. Microsoft says its genuine error and warning messages do not include a phone number.
Press Alt+F4 to close the active window. If the browser is trapped in a loop, press Ctrl+Shift+Esc to open Task Manager, select the browser, and choose End task. This closes the browser process; do not select buttons inside the warning.
3
Reopen the browser without restoring the page
Start the browser again and decline any prompt to restore the previous tabs. If the warning immediately returns, close the browser and review its startup pages and extensions before browsing normally.
4
Check whether it is a website notification
A website notification can appear in the corner of the Windows desktop even when the site is not open. In Edge, open Settings > Privacy, search, and services > Site permissions > All sites. In Chrome, open Settings > Privacy and security > Site settings > Notifications. Block only the unfamiliar site that sent the warning.
Open the browser's Extensions page and Windows Settings > Apps > Installed apps. Remove an extension or app only when you do not recognize it or it appeared when the warnings began. Keep legitimate antivirus protection turned on.
6
Run a scan in Windows Security
Save your work, open Windows Security > Virus & threat protection, install available protection updates, and run a Full scan. Use Microsoft Defender Offline only if warnings continue outside the browser or malware may be persistent. The offline scan restarts the PC.
If you installed remote-access software for a caller, disconnect the PC from the internet and remove that software. Change exposed passwords from a different trusted device. Contact the card issuer or bank immediately if you shared payment details or sent money.
Use Microsoft's official reporting route, restart Windows, and confirm that the warning stays gone. Re-enable an extension only when you recognize it and need it.
If the alert comes from an antivirus app you knowingly installed, open that app from the Start menu and review its scan history. Do not disable a real protection warning just because it looks similar to a browser pop-up.
If the warning returns only in one browser, recheck that browser's notification permissions, extensions, and startup pages before resetting Windows.
If Windows Security finds a threat it cannot remove, keep the detection name and use Microsoft's malware-removal guidance or a trusted local technician. Do not call the number shown by the pop-up.
ⓘ Sources and verification
Checked against official documentation on . Scope: Windows 10 or Windows 11.
The written procedure follows current Microsoft scam-response and Windows Security guidance plus current Edge and Chrome notification controls. The preserved video may show older browser labels.
