Microsoft Defender: Is Your PC Really Protected?

For years, Windows users were told: "The first thing to do on a new PC is install an antivirus." In 2025, that advice is not only outdated—it might actually hurt your PC's performance.

1. The Test Results are In 

Independent labs like AV-Test and AV-Comparatives consistently give Microsoft Defender top marks.

It detects zero-day malware just as effectively as paid competitors like Norton or McAfee, without slowing down your system with constant "Upgrade Now" pop-ups.

2. Hidden Features You Must Enable

Defender is great out of the box, but to be truly bulletproof, you need to turn on these two advanced features manually:

• Ransomware Protection: Go to Virus & threat protection > Ransomware protection and turn on "Controlled folder access." This prevents unauthorized apps from encrypting or modifying your documents.
• Core Isolation: In Device Security, ensure "Memory Integrity" is ON. This uses virtualization to block malicious code from injecting itself into high-security processes.
• SmartScreen: It blocks phishing sites and malicious downloads in Edge (and Chrome/Firefox via extension).

3. Free vs. Paid: Do You Need to Pay?

For 95% of home users, Defender is enough. Consider a paid suite ONLY if you need the bundled extras (VPN, advanced parental controls) or if you are extremely prone to clicking phishing links.