Windows has more antivirus programs than we can count, and none of them are quite perfect. Microsoft Security Essentials is a completely free application that protects against viruses, spyware, and other malware. It was one of only three products that did well at both finding and removing malware, including the leftovers. The Windows Firewall has plenty of capability for handling outbound connections if you really need that level of paranoia. It’s better to focus on keeping malware off your PC in the first place.”]
Source: https://lifehacker.com/stop-paying-for-windows-security-microsofts-security-t-5401453