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In short: In July and August 2026, the test lab AV-TEST evaluated 15 security products for Windows 11. All of them scored at least 17.5 of 18 points and earned the TOP PRODUCT award, and twelve achieved a perfect score. The free, built-in Microsoft Defender blocked 100 percent of attacks but slowed software installation somewhat. For most home users, Defender is enough if Windows stays up to date.
How AV-TEST scores
Each product can earn up to 6 points for protection, performance and usability, so 18 points is the maximum. From 10 points a product gets the AV-TEST seal, and from 17.5 points the TOP PRODUCT award. Products run with default settings and may update at any time.
Results
| Product group | Score |
|---|---|
| AhnLab, Avast Free, AVG Free, Avira, Bitdefender, ESET, F-Secure, K7, Kaspersky, Malwarebytes, McAfee, Norton 360 | 6 / 6 / 6 |
| Spyhunter | 5.5 / 6 / 6 |
| Microsoft Defender, TotalAV | 6 / 5.5 / 6 |
Data from AV-TEST, July to August 2026 (protection / performance / usability).
Microsoft Defender in detail
Defender detected all 297 zero-day attacks and all 12,543 samples in the reference set, with no false positives. Installing applications on a standard PC took 44 percent longer than without security software, which cost half a point for performance. Two free products, Avast Free and AVG Free, reached a perfect score.
Free or paid?
Germany's Federal Office for Information Security (BSI) recommends keeping antivirus and firewall enabled and notes that free versions usually have fewer features. Paid suites add extras such as password managers, VPNs or parental controls. On 21 October 2026, AV-TEST also published a six-month endurance test of 13 suites on Windows 11.
Tips
Install updates promptly, as shown in our guide to the October 2026 Patch Tuesday, use only one real-time scanner, download software from vendor sites and learn to spot phishing with our phishing guide.
How to check that Defender is active
Open Settings, choose Privacy & security and then Windows Security. Under Virus & threat protection you can see whether real-time protection is on and when the last scan ran. In the same area you can switch on controlled folder access, which helps protect your documents against ransomware. If you install a paid suite, Windows normally switches Defender to passive mode so that the two programs do not get in each other's way. Keep the Windows firewall turned on, as it is by default, and never disable protection just to install a program from an unknown source.
Who should buy what
Most home users are fine with Defender. Families with many devices may prefer a paid suite with multi-platform licences and parental controls. More guides are in our antivirus category.
Sources
