Do you still need antivirus on Windows 11?

Every copy of Windows 11 includes Microsoft Defender Antivirus, switched on by default and updated automatically through Windows Update. It isn't a token effort: it scans files as they're opened, checks downloads against Microsoft's cloud reputation service, and regularly performs well in independent lab testing alongside paid products.

So the honest answer to the question is that most people using Windows 11 are already running antivirus, whether they've noticed or not. Whether it's worth paying for a third-party suite on top is a different question — and it depends less on the scanner than on what else comes in the box.

What Windows 11 already covers

Open Windows Security from the Start menu and you'll find more than a scanner:

• Virus & threat protection — real-time scanning, cloud-delivered protection, and on-demand quick, full and offline scans.
• Firewall & network protection — the built-in Windows firewall, on by default.
• App & browser control — reputation-based protection, which warns about or blocks unrecognised apps, malicious sites in Microsoft Edge, and potentially unwanted apps such as bundled adware.
• Ransomware protection — Controlled folder access, which stops unknown programs changing files in protected folders. It's off by default, because it occasionally blocks legitimate software, but it's worth considering.
• Device security — hardware features like Secure Boot and memory integrity, which make it harder for malware to take hold at a deep level.

Some newer installations also include Smart App Control, which blocks apps that are unsigned or have no established reputation. If it's available and on, it's a strong extra layer.

If you want to understand the scanning side in more detail, real-time protection versus a full scan explains what each actually does.

What a paid suite usually adds

The core scanning engine is rarely the main difference now. Third-party suites typically compete on extras, and it's the extras you're really deciding about:

Feature	Built into Windows 11?	Worth noting
Real-time malware scanning	Yes	Comparable protection in independent tests
Firewall	Yes	Paid versions may add friendlier controls
Phishing and malicious site warnings	Yes, strongest in Edge	Suites often extend this to other browsers
VPN	No	Often has data limits in bundled versions
Password manager	Partly, via the browser	Free standalone options also exist
Parental controls	Yes, via Microsoft Family Safety	Suites may offer more detailed filtering
Identity or dark web monitoring	No	Alerts only; it can't undo a breach
Cover for phones and Macs	No	Useful if you want one dashboard for a household

Look at that list and ask which extras you'd actually use. If the answer is "the VPN and cover for three phones", a bundle can be good value compared with buying things separately. If the answer is "none of them", you'd mainly be paying for a second scanner that does the same job as the first.

When a third-party suite can make sense

• You manage security for several people or devices and want one place to check them all, including non-Windows devices.
• You'd genuinely use the bundled tools, and they'd replace things you'd otherwise pay for separately.
• You prefer another browser and want web protection that works the same way in it.
• You want someone to ask. Some paid products include support from the provider, which can be reassuring for less confident users.

When built-in protection is enough

For one person on one Windows 11 machine, with updates switched on, sensible habits and a browser kept up to date, Microsoft Defender is a reasonable place to stop. The things that most often lead to trouble — reused passwords, phishing emails, fake download sites, ignoring updates — aren't fixed by any scanner. Two-step verification on your important accounts and a password manager will usually do more for you than a second layer of antivirus.

One point to be clear on: you should run one real-time scanner, not two. When you install a third-party antivirus, Windows automatically steps Defender back so they don't clash. If you later remove that product, Defender switches itself back on. Windows Security also has an option called Periodic scanning, which lets Defender run occasional scans alongside another product without competing for real-time protection.

A five-minute check either way

1. Open Windows Security and look at Virus & threat protection. It should name the active scanner and show no warnings.
2. Under Virus & threat protection settings, check that real-time protection, cloud-delivered protection and Tamper Protection are on.
3. Under App & browser control, check reputation-based protection is on, including potentially unwanted app blocking.
4. If a third-party suite is listed, confirm it's the one you meant to keep, and that it isn't an expired trial that came with the computer.
5. Run Windows Update, since Defender's engine and definitions arrive through it.

If you're paying for a suite already, note its renewal date and price. Many start with a discounted first year and renew automatically at a higher rate. Renewal, refund and cancellation terms are set by the provider that bills you, so check its account page or contact it directly — and fold it into your yearly security subscription review so the decision gets made on purpose, not by default.