Microsoft Defender (section 3.1) protects most Windows PCs by default and is enough for careful everyday use. Third-party antivirus is optional—choose it if you want a different vendor, extra features (VPN bundles, parental controls), or IT policy requirements. Install only one real-time antivirus at a time; two products fighting each other cause slowdowns and missed threats. Always download from the official website, never from cracked bundles or unknown download hubs.
Most widely used options (overview)
Ranked by approximate global consumer popularity and install base among third-party products (2024–2025 industry reports and vendor disclosures). Defender is excluded here because it is built into Windows—already the most common protection worldwide.
| Rank | Product | Typical model | Best known for |
|---|---|---|---|
| 1 | Avast | Free + paid suites | Very large free install base; easy setup |
| 2 | AVG | Free + paid (same group as Avast) | Mainstream free antivirus for casual users |
| 3 | Norton | Subscription suites | Long-standing consumer brand; identity extras |
| 4 | McAfee | OEM bundles + subscription | Often pre-installed on new PCs |
| 5 | Bitdefender | Free + paid | Top independent lab scores; low impact |
| 6 | Kaspersky | Free + paid | Strong detection; deep settings |
| 7 | ESET NOD32 | Paid (trial available) | Lightweight feel; popular in Europe |
| 8 | Huorong Security (火绒) | Free | Quiet, low ads; dominant in China |
| 9 | Malwarebytes | Free scan + paid Premium | Second-opinion / anti-malware add-on |
| 10 | Avira | Free + paid (Gen group) | Classic free tier; cloud scanning |
Product details (by popularity)
Trademarks belong to their respective owners. Rank numbers match the table above.
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1Avast Free Antivirus / Premium Security
One of the world’s largest third-party antivirus user bases. Free edition covers real-time protection; paid tiers add firewall, ransomware shield, and VPN bundles.
- Strengths: Easy onboarding; frequent updates; strong community help articles.
- Trade-offs: Free version shows upgrade prompts; review privacy/data settings if that matters to you.
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2AVG AntiVirus Free / Internet Security
Sister brand to Avast (Gen). Similar engine and massive free-user share—common choice for users who want a familiar, installer-guided experience.
- Strengths: Straightforward UI; acceptable scores in many independent tests.
- Trade-offs: Installer may offer optional bundled software—read each screen and decline extras you do not want.
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3Norton 360 / AntiVirus Plus
Historic U.S. consumer security brand (Gen). Sold mainly as subscriptions with cloud backup, password manager, and VPN on higher tiers—often bundled with retail PCs and ISPs.
- Strengths: All-in-one suites; strong brand support; good for users who want one bill for several security tools.
- Trade-offs: Subscription cost; full suites can feel heavy compared with Defender alone.
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4McAfee Total Protection
Frequently pre-loaded on new laptops (trial subscriptions). Large global footprint through OEM partnerships and multi-device family plans.
- Strengths: Cross-platform licenses (Windows, Mac, Android); identity monitoring on premium plans.
- Trade-offs: Trial nag screens on new PCs; uninstall cleanly if you prefer Defender—do not run both in real time.
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5Bitdefender Antivirus Free / Total Security
Consistently top-ranked in AV-TEST and AV-Comparatives. Popular with users who want strong detection without the bloat of old-style “suites.”
- Strengths: Excellent lab scores; relatively low system impact; clear paid upgrade path.
- Trade-offs: Free edition is more limited than Avast/AVG; best features require subscription.
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6Kaspersky Standard / Plus / Premium
Major vendor with decades of malware research. Offers a free baseline in some regions and deep configuration for advanced users.
- Strengths: Strong detection in lab reports; granular controls; optional VPN and password tools on paid tiers.
- Trade-offs: Some governments and employers restrict supplier choice—check current workplace or national guidance before deploying.
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7ESET NOD32 Antivirus / Smart Security
Slovak vendor especially popular in Europe and among users who want a smaller footprint than legacy suites. Known for fast scans and gamer-friendly options.
- Strengths: Lightweight reputation; solid technical support; good for older hardware.
- Trade-offs: No permanent free real-time tier—trial then paid for full protection.
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8Huorong Security (火绒安全)
Among the most installed third-party choices in mainland China. Praised for staying quiet—few pop-ups—and for 弹窗拦截 (popup blocking) that stops adware from other apps.
- Strengths: Low annoyance; sensible blocking of bundled installers; free for personal use.
- Trade-offs: English documentation is limited; less common outside Chinese-speaking markets.
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9Malwarebytes Free / Premium
Huge user base for on-demand scans and cleanup. Premium adds real-time protection—often used when users want a second opinion alongside Defender, but do not run two real-time engines without planning (Premium replaces Defender’s role).
- Strengths: Excellent at removing adware/PUPs; simple scan workflow.
- Trade-offs: Free version does not replace full-time antivirus; Premium is a separate subscription.
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10Avira Free Security / Prime
German-origin product (Gen group). Long-running free tier with cloud-assisted scanning—still widely downloaded though less dominant than Avast/AVG in recent share reports.
- Strengths: Free baseline; browser safety extensions; optional VPN/optimizer bundles.
- Trade-offs: Upsell prompts in free version; bundled “Speedup” features are optional—skip if you do not need them.
Products to avoid
- “PC Cleaner / Speed Booster / Windows Optimizer” tools that mimic antivirus branding—often adware or scareware.
- Unknown brands from popup ads or bundled installers with no independent test history.
- Cracked or “all-in-one activator” packs—common malware delivery method.
- Two real-time antivirus programs at once (e.g., Norton + McAfee)—pick one primary provider.
Choosing and installing safely
- Check recent scores from independent labs (AV-TEST, AV-Comparatives, MRG Effitas)—not just marketing claims.
- Match product to region: Huorong for quiet daily use in China; Bitdefender / ESET / Kaspersky for strong global lab results; Avast / AVG / Avira if you want a free tier.
- After install, open Windows Security (3.1)—Windows should register the new app as the active antivirus provider.
- If switching products, uninstall the old suite first; use the vendor’s removal tool if drivers remain.
- Decline optional browser toolbars, VPN trials, and registry cleaners during setup unless you explicitly want them.
Note: Market share estimates vary by region and change over time. Ranks above reflect broad consumer popularity among third-party Windows antivirus—not detection quality alone. For most home users, Defender + safe habits (section 3.1) remains the simplest path; add third-party software only when you have a clear reason. A shorter comparison also appears in section 5.2 (Common Tools).