Avast

ClamWin Free Antivirus is an open-source antivirus tool for Windows with a graphical user interface that offers high detection rates for viruses and spyware, a scanning scheduler, and automatic downloads of a regularly updated virus database.

Clam AntiVirus (ClamAV) is an open-source, cross-platform antivirus engine for detecting trojans, viruses, malware & other malicious threats.

Malwarebytes is an antivirus and anti-malware software that removes malicious software, prevents threats in real-time, crushes ransomware, defends against harmful sites, and cleans and removes malware.

MacKeeper is an antivirus and anti-malware that helps Mac users streamline performance optimization and data protection operations via a unified platform.

Sophos Home is a feature-rich antivirus solution that includes real-time and on-demand virus protection, anti-ransomware, anti-phishing, firewall, parental control-type content filtering, keylogger protection, and more.

F‑Secure SAFE is an antivirus and internet security suite for all devices, including browsing protection, banking protection, parental control, and more.

Bitdefender is an antivirus that consistently ranks at the top of antivirus at independent testing. The free version for windows offers the same core antivirus technology found in their commercial plan.

Avira antivirus provides complete virus protection for Windows computers with various security, privacy, and performance tools.