Warning pop-ups

Security warning: your computer has been locked

Dangerous malware has been found on your computer (error code 0x80070422).

Hard disk failure detected — your hardware is damaged.

Your user account has been compromised. Your passwords, photos and bank details are at risk.

Do NOT switch off your computer. Call technical support immediately:

• ✗ Call the number — someone there will help. – That's exactly what the scammers want. On the phone they'll talk you into allowing remote access or paying for a supposed repair.
• ✗ Click “OK” or “Start scan” in the window. – Buttons in this window belong to the scammers. A click often starts a download or opens even more windows.
• ✓ Close the window or browser tab (the tab at the top of the browser) — Ctrl + W, on a Mac ⌘ + W. – Right. It's just a web page dressed up as a warning. Closing it is enough. If the keyboard doesn't respond, hold down the Esc key for two seconds — the browser then leaves full screen. If that doesn't work either, quit the browser: on Windows, if necessary, via the Task Manager (Ctrl + Shift + Esc); on a Mac with ⌘ + Option + Esc. If the browser then offers to restore your last pages: say no — otherwise the warning is back.
• ✓ Restart the computer. – Also fine: a restart ends the web page. The threat “do NOT switch off” is part of the trick. Afterwards: if the browser offers to restore your last pages, say no — otherwise it opens the warning again straight away.

A trap. Real security software doesn't show you a phone number to call. A web page can't even tell whether your hard disk is broken or an account has been taken over. The window is a web page in full screen — and it can be closed.

Your device is slow! 17 problems found

Storage 94% full

Battery damaged — act now

Install the cleaning app now and rescue your device.

• ✗ Tap “Clean now” and install the app. – Apps like this often secretly cost money through a subscription, show ads or spy on you. A web page can at most see your battery's charge level — it can't detect any damage.
• ✗ Try “Start scan” first — it can't hurt. – The “scan” is just an animation. It's meant to impress you so that you install afterwards.
• ✓ Close the page and carry on. – Right. It's advertising dressed up as a warning. Real information about storage or battery is shown by your device in its own settings.

A trap. Web pages can't detect battery damage or full storage — “warnings” like this are advertising with scare tactics.

Confirm that you are human

Press the Windows key and R at the same time.

Press Ctrl + V to paste the verification code.

Press Enter.

• ✗ Follow the three steps — it's only a check. – That's the trap: the page has secretly put a command on your clipboard. With Windows + R, paste and Enter you run it yourself — and bring malware onto your computer.
• ✓ Close the page and don't type anything. – Right. No genuine check asks you to press key combinations or paste something into a window on your computer. Pages that want that are a scam.
• ✓ Ask someone who knows about computers before doing anything. – Also good: ask first, act later. The answer will be: close the page, type nothing.

A trap (experts call it “ClickFix”). No web page needs you to paste commands into Windows + R, a terminal or PowerShell — however real the check looks.

Critical browser update required

This page can't be displayed because your browser is no longer secure.

Download the latest version now to continue.

• ✗ Click “Update now” and open the file. – The downloaded file isn't an update, it's malware. Real browser updates don't come through a web page.
• ✗ Keep reloading the page until it works again. – Reloading changes nothing — the prompt is part of the page itself. Close it.
• ✓ Close the page and, if needed, check for an update in the browser's settings. – Right. The browser brings its own updates — automatically or through its settings, not through a web page you happen to visit.

A trap. Updates for your browser come through its settings or automatically, not through a web page. The message is bait for a file containing malware.

Updates available

Security updates are ready for your device.

You can install them now or choose a later time.

• ✓ Install now. – Good. Updates through your system settings close security holes. Save any important work first.
• ✓ Remind me later and install tonight. – Also fine — just don't put it off forever. Security updates matter.
• ✗ This is surely a scam too — always dismiss it. – This message comes from the system itself, not from a browser window: no phone number, no panic, no deadline, no download from a web page. Ignoring real updates for good makes your device less safe.

Genuine. The message comes from your system settings, shows no phone number and applies no pressure. Not everything that pops up is a trap.