Windows Virus Protection Explained
Virus protection on Windows is not one feature but a stack: reputation filtering at download, real-time scanning at write and execute, behavioural monitoring at runtime, a firewall at the network edge and folder access control for ransomware.
Products covered on this page
The built-in layers
SmartScreen scores downloads and sites by reputation. Microsoft Defender scans in real time and via cloud lookups. Windows Firewall blocks unsolicited inbound traffic. Controlled folder access restricts which applications can modify your documents.
What third-party products add
Browser-independent web filtering, ransomware rollback, rescue media, cross-platform coverage and support. Detection improvements are real but modest for a typical home user.
Frequently asked questions
- How do I turn on virus protection in Windows?
- Open Windows Security → Virus & threat protection and make sure real-time protection is on. It is enabled by default unless a third-party antivirus has taken over.
- Does Windows virus protection cost anything?
- No. Microsoft Defender is included with Windows at no additional cost.