It fills your whole screen out of nowhere: "Windows Defender Security Warning — your computer is infected. Do not restart. Call this number immediately." Maybe there's loud beeping, and your browser won't close. Take a breath — it's fake, and your computer almost certainly isn't infected (yet). Here's how to get rid of it.
How to know it's a scam
The giveaway is the phone number. Real Windows Defender — and real Microsoft — will never show you a popup telling you to call a number, and never lock your screen with an alarm. That's a "tech support scam" (scareware): the popup is just a web page designed to panic you into calling. The person who answers will either charge you to "fix" a problem you don't have, or talk you into letting them remote into your machine — which is when the real damage starts.
How to get rid of it
- Do not call the number. That's the whole goal of the popup — don't give it what it wants.
- Close the browser. Try Esc or Alt + F4 first. If it won't close, open Task Manager (Ctrl + Shift + Esc), find your browser, and click End task.
- Don't reopen your tabs. When the browser restarts, decline "restore previous session" — that just brings the scam page back. Clear your browsing data for good measure.
- Run a real scan. Open Windows Security → Virus & threat protection → Full scan (or Malwarebytes) to confirm nothing actually slipped through.
If you already called or let them in
If you called the number and let someone remote into your computer, treat it as compromised. Disconnect from the internet, change your important passwords from a different device (email and banking first), and get the machine properly cleaned — a real removal, not just a scan, because remote-access tools and info-stealers can hide.
That's a job we do all the time. If you let a fake "Microsoft tech" into your PC, bring it to us and we'll make sure it's actually clean. Dawsonville & all of North Georgia, in person or remote — (706) 203-2563.