Do you need to buy antivirus?

For most people using Windows 10 or Windows 11, the protection built into Windows is enough. You do not need to buy an antivirus, and you should be wary of anything that pops up telling you your computer is infected and you must pay to fix it.

What Windows already has

Windows Security (earlier called Windows Defender) is antivirus, firewall and web protection built into Windows, and it is updated automatically. Check it is on:

1. Open Start and search for Windows Security.
2. You want green ticks beside Virus & threat protection and Firewall & network protection.
3. Under Virus & threat protection, Protection updates should say recently updated.

If you install another antivirus, Windows Security steps aside. Two antivirus programs at once slow the laptop without protecting it more.

What actually keeps you safe

Antivirus catches known threats. Most real problems come in through people being tricked, which no antivirus fully prevents:

• Keep Windows and your browser updated. Updates close the holes that malware uses.
• Download software only from the maker's website or the Microsoft Store, never "cracked" or free versions of paid programs from random sites. These are the most common source of infections.
• Do not open attachments you were not expecting, even from someone you know.
• Scan flash drives that have been in other computers. See the shortcut virus.
• Ignore pop-ups in the browser that say your computer is infected. They are adverts, not warnings.

Phones

Android: Google Play Protect is built in and scans apps. Install apps only from the Play Store, and be careful with any app asking for accessibility or "display over other apps" permissions that it does not obviously need.

iPhone: apps come only from the App Store and cannot interfere with each other. You do not need an antivirus app.

Signs something has got in

• Pop-ups and adverts appearing even when the browser is closed.
• A browser home page or search engine that changed itself.
• New toolbars or programs you did not install.
• The laptop suddenly much slower, with a program you do not recognise using the CPU.
• Friends receiving messages or emails you did not send.

If you think you are infected

1. Disconnect from the internet.
2. Open Windows Security, Virus & threat protection, Scan options, and run Microsoft Defender Offline scan. The laptop restarts and scans before Windows loads.
3. Uninstall any program you do not recognise in Settings, Apps.
4. Reset your browser settings (Chrome: Settings, Reset settings).
5. From a different device, change your email and banking passwords.

When a paid antivirus makes sense

If you are on an old, unsupported version of Windows, or you share a computer with many people (a shop, an office, a cyber café), a reputable paid product with central management can be worth it. For everyone else, spend the money on a backup drive.