Good news: if you use Windows 10 or 11, you already have antivirus. Microsoft Defender Antivirus is built into Windows and runs in the background through the Windows Security app. For most people, it is all the antivirus they need.

Check that it is on

  1. Open Start and search for Windows Security.
  2. Open Virus & threat protection.
  3. Make sure real-time protection is on and protection updates are current.
  4. Run a Quick scan now and then.

When third-party antivirus makes sense

Free antivirus from well-known security companies is also available. You might choose one if you want extra features, but avoid running two real-time scanners at once. Download only from the company’s official website.

Habits that matter more than software

  • Keep Windows updated (Settings → Windows Update).
  • Never use cracked software or “activators”; they are a common source of malware.
  • Download apps only from official sites or the Microsoft Store.
  • Be careful with USB drives passed around at cyber cafés, printing shops and offices; scan them.
  • Do not open unexpected email attachments. See how to spot phishing messages.
  • Back up important files to an external drive or the cloud, in case of ransomware.

Still on Windows 10?

Microsoft ended Windows 10 support on 14 October 2025, so the system no longer gets regular security updates. Microsoft says Defender security intelligence updates continue for a period, but an unpatched operating system is still risky. Upgrade to Windows 11 if your PC supports it, or look at Microsoft’s paid Extended Security Updates.

Fake “your PC is infected” pop-ups in the browser are scams. Close the tab. Never call the number shown or install what they offer.

PC slow? See how to speed up a slow Windows laptop.

This guide was checked in October 2026. Menus and services change, so if something looks different on your phone, check with your provider.

Common questions

Do I need antivirus on Windows 11?

Windows includes Microsoft Defender Antivirus. Keep it on and updated; for most home users that, plus safe habits, is enough.

Is Microsoft Defender good enough?

For most people, yes, when kept updated and combined with safe browsing and downloads.

Should I install two antivirus programs?

No. Running two real-time antivirus programs can cause conflicts and slow your PC.

What about Windows 10?

Windows 10 support ended on 14 October 2025. Microsoft says Defender security intelligence updates continue for a time, but the system itself no longer gets regular security updates.

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