Windows Security · 6 min read
Do You Need Antivirus Software on Windows?
You already have antivirus on Windows. Microsoft Defender is built into Windows 10 and Windows 11 and runs by default unless another product takes over. The real question is whether to replace it.
Published 2026-08-09 · Last updated 2026-08-09
What Defender already covers
Real-time file scanning, cloud-delivered protection, SmartScreen reputation filtering for downloads and sites, a firewall, exploit protection, and a pre-boot offline scan mode for stubborn infections. Controlled folder access adds ransomware protection — though it is off by default.
Reasons to install something else
Cross-platform coverage from one subscription. Browser-independent web filtering if you live in Chrome or Firefox rather than Edge. A bundled VPN, password manager or identity monitoring. Remote management of family PCs. A support line. Those are legitimate reasons.
Reasons that are not good enough
'Free means worse' is not true here — Defender ships as part of a commercial operating system. 'My PC feels slow so I need antivirus' usually points to storage, RAM or startup programs. 'A pop-up said I have 5 viruses' is itself the threat.
The minimum viable setup
Keep Windows Update on automatic. Enable controlled folder access. Use a modern browser with an ad blocker. Keep the free version of Malwarebytes for second opinions. Back up important files to a disconnected drive or a cloud service with version history. That combination costs nothing and beats a paid suite on a neglected machine.
Frequently asked questions
- Does Windows 11 come with antivirus?
- Yes. Microsoft Defender Antivirus is built in and enabled by default via the Windows Security app.
- Is Defender enough for online banking?
- Combined with a patched browser, unique passwords and multi-factor authentication, yes. Some suites add a hardened banking browser, which is a convenience layer rather than a requirement.