We should all know the rules of how to protect our privacy and internet security and keep Windows secure: Don't open mysterious messages and emails, don't give out personal information, don't tap questionable links or download apps from shady sites, use secure passwords, and keep your Windows software up to date.
You can also take a few extra internet security steps to make sure you're safe online with a PC: Use a VPN to protect your internet traffic, a password manager to keep track of login credentials, and an end-to-end encrypted messaging app to keep people from spying on your communications. But if you are looking for legitimate software to keep your Windows device secure, a good first step is to run the best antivirus software. The best antivirus suite and antivirus tools monitor your app downloads and watch for malicious software and suspicious software behavior.
And here's the first important thing for you to know about the best antivirus software and antivirus products: Microsoft Defender -- the free antivirus program and internet security software that comes free with Windows 10 and until recently was called Microsoft Windows Defender -- does a fine job of protecting your PC and providing internet security. (Amazingly, Microsoft provided no built-in protection for Windows back in the days of Windows 98 and XP.) Using Microsoft Defender should be your starting point for the best antivirus security on Windows, and most users will find they don't need to go any further.
However, you can make the case that the Windows security ecosystem is healthier when users don't depend on just one company for protection from a virus or malware. If you favor robust platform diversity, you can easily find solid virus or malware protection from third-party security companies that are up to the task of guarding your PC for free. And most let you also protect all your devices with an annual subscription -- though, it's important to note, that's largely unnecessary outside the Windows realm.
To that end, we've put together a list of the best antivirus products for Windows, encompassing both free antivirus programs and subscription options. These picks of the best antivirus programs are a combination of recommendations from independent third-party labs AV-Test and AV-Comparatives and our hands-on testing.
Note that the free and paid security services discussed here are independently chosen by our editors. We're in the process of updating this full list, so check back for an update.
Update, October 21: This list previously included Avast's antivirus as an alternate free choice, but we've pulled that recommendation in light of a report from Avast that its internal network was breached this year, possibly to insert malware into its CCleaner software. This is the second such security issue from Avast in under 3 years.