It usually happens on a perfectly ordinary afternoon. You're browsing the web, maybe reading the news or checking a recipe, and suddenly your screen fills with a blaring red or blue warning. A robotic voice might start talking. The message looks completely official — Microsoft branding, a Windows logo, urgent capital letters. It tells you your computer has been infected, your files are at risk, your bank details may have been stolen. And it gives you a phone number to call. Right now.

People bring laptops into us after this happens several times a week. Almost every single time, the computer itself is absolutely fine. But a handful of those customers have already called the number — and that's when the real trouble starts.

What You're Actually Looking At

This is called a tech support scam, and it's one of the most effective cons going because it exploits exactly the right emotion: panic. The "warning" isn't from Microsoft, Windows, your bank, or any authority. It's a webpage — sometimes one you landed on accidentally, sometimes triggered by a dodgy advert on an otherwise legitimate site — designed to look terrifying enough that you reach for the phone without thinking.

The alarm sound, the full-screen takeover, the flashing colours: all of it is theatre. Browser windows can do all of these things without having any access to your actual computer. Nothing has been scanned. Nothing has been detected. The message is identical whether your machine is brand new or ten years old, infected or completely clean.

What Happens If You Call the Number

This is where things go genuinely wrong. The person who answers will sound professional and helpful. They'll ask you to install a remote-access tool — something like AnyDesk or TeamViewer, which are legitimate programs — so they can "fix" the problem. Once they have access, several things can happen:

  • They browse your files, looking for banking details, saved passwords, or anything valuable.
  • They show you alarming-looking (but meaningless) system data to "prove" the infection is real.
  • They ask for payment — often hundreds of pounds — to remove a threat that was never there.
  • In some cases, they install actual malware while they have access, so they can return later.

The victims are often careful, sensible people. These scammers are very good at what they do.

The One Thing You Must Do (and the One Thing You Must Not)

Do not call the number. Do not click anything inside the warning. Do not enter any details.

What you should do is close the browser. If the page won't close — and they're sometimes designed to resist it — try these steps:

  1. Press Ctrl + W to close the current tab.
  2. If that doesn't work, press Alt + F4 to close the whole browser window.
  3. If the window is still stuck, press Ctrl + Alt + Delete, open Task Manager, find your browser in the list, and click End Task.
  4. When you reopen your browser, it may ask if you want to restore your previous session — click No, or you'll just reopen the same page.

Once it's closed, the threat is gone. You can breathe.

How to Tell a Real Windows Warning From a Fake One

Real warnings from Windows appear as small notifications in the bottom-right corner of your screen, or within the Windows Security app itself — never as a full-screen webpage with a phone number. Microsoft will never cold-call you, and they will never display a phone number in a warning message and ask you to ring it. If a "warning" is asking you to call someone, it's a scam. Full stop.

A few other telltale signs:

  • The warning appeared while you were using a web browser, not out of nowhere on a blank screen.
  • There's a phone number prominently displayed — real system alerts don't do this.
  • The page plays audio automatically, often a robotic voice reading the "alert" aloud.
  • The message claims to have already scanned your PC and found specific threats — browsers can't do that.
  • Closing the tab seems difficult or impossible without a workaround.

What If You've Already Called — or Already Given Access?

If you've already spoken to someone and let them connect to your computer, act quickly. Disconnect from the internet immediately (unplug your ethernet cable or turn off Wi-Fi). Change your important passwords — email, banking, anything saved in your browser — from a different device if you can. Contact your bank if any financial details may have been visible.

Then bring the machine in. After a remote-access scam, it genuinely needs to be checked over properly. We run through full malware and security checks to make sure nothing was left behind during that session, and we can advise on what else may need to be done based on exactly what happened.

The practical takeaway is simple: a genuine emergency on your computer will never ask you to ring a stranger. If your screen fills with panic and a phone number, take a breath, close the browser using the steps above, and carry on with your afternoon. The computer is almost certainly fine — and if you're not sure, we're here to check.