Fake Microsoft pop-up saying "call this number": what to do
A pop-up says your PC is infected and to call Microsoft? It's a scam. Here's what to do right now, and what to do if you already let the caller in.
If a pop-up says your computer is infected, locked or "compromised" and tells you to call a Microsoft number, it's a scam. Microsoft doesn't put phone numbers in warning pop-ups. Don't call. Close the browser, and if it won't close, restart the PC.
What the pop-up usually says
These pages often fill the whole screen, play a loud alarm or a recorded voice, and show a fake Windows or "Windows Defender" logo. Common lines are "Your computer has been blocked", "Do not restart your computer" and "Call Microsoft Support" with a toll-free number. Some show your IP address to look official. None of this means your PC is really infected. It's a web page.
Is the pop-up real?
No. Microsoft says its error and warning messages never include a phone number, and that it doesn't call people out of the blue to offer support (Microsoft Support). A real Windows Security alert shows up in the Windows Security app or as a small notice near the clock, not as a full-screen web page with an alarm.
A few signs it's fake:
- It appears while you're browsing, inside Chrome, Edge or Firefox.
- It shows a phone number and tells you to call now.
- It says not to turn off or restart your computer.
- It plays a sound or a voice and won't let you close the tab.
If you're not sure, don't use anything on the pop-up. Close the browser as shown below, then open the Windows Security app from the Start menu and run a quick scan. If that scan finds nothing, the warning was only a web page.
How to close it
- Press Ctrl + Shift + Esc to open Task Manager.
- Click your browser (Chrome, Edge or Firefox) and choose End task.
- When you open the browser again, don't restore the old tabs.
If that doesn't work, hold the power button until the PC turns off, then turn it back on.
If the pop-ups keep coming back
These pages usually come from a bad ad on an ordinary website, or from mistyping a web address. If you see them again and again, check whether a website has been allowed to send you notifications. Those appear in the corner of the screen even when the site isn’t open. In Edge or Chrome, open Settings, then the site permissions or privacy section, then Notifications, and remove any site you don’t recognize. Then look through your browser’s extensions and remove any you didn’t add.
If you already called
The caller's next step is almost always to ask you to install a program such as AnyDesk, TeamViewer or Quick Assist, or to read out a code. That gives them control of your computer. If you haven't done that yet, hang up. A real Microsoft employee won't call you back. To see how the rest of that call usually goes, read how fake Microsoft support calls work.
If you already let them in
This happens to careful people every day. The callers are trained and persuasive. What matters now is acting quickly:
- Disconnect the PC from the internet (unplug the cable or turn off Wi-Fi).
- Hang up.
- Call your bank from another phone, using the number on the back of your card.
- Change your email password from another device.
- Follow our two-minute checklist.
Then report it at ReportFraud.ftc.gov and ic3.gov. You can also tell Microsoft at microsoft.com/reportascam.
How common this is
The FBI's IC3 2025 Internet Crime Report lists 47,794 tech-support scam complaints and $2,134,675,818 in reported losses, about $44,000 per complaint (IC3 2025 report).
Making the next attempt harder
The scam only works when someone at the PC lets the caller connect. Xcelcor Guardian is a Windows 11 app that holds new connections from common remote access tools (AnyDesk, TeamViewer, Quick Assist, ScreenConnect, RDP and others) until the account holder, often a son or daughter, approves it by email or on xcelcor.com. The PC itself only has a Refuse button. It doesn't see the screen, files, passwords or banking, and it works alongside your antivirus. It lowers the risk, but it doesn't stop every scam. You can try it free for 14 days on one PC, no card needed.
Related: how the fake Microsoft support scam works and what a remote access scam looks like.
More: how to block remote access on Windows 11 and how to protect an elderly parent’s computer from far away.
If the caller asked for Quick Assist, here is how to turn off Quick Assist on Windows 11 Home.
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