If you are just using Microsoft’s built-in antivirus tools to protect your PC, you are already make mistakes. Either invest in a paid solution or else download a free version from the top vendors. No antivirus solution is perfect, but you need to give yourself a fighting chance. Here, are the antivirus that people choose a most. As for me, I'm used to kaspersky..
Bitdefender Antivirus Plus 2015
Bitdefender's engine is one of the most accurate and reliable around. An excellent antiphishing module alerts you to malicious links in your search engine results, and blocks access to dangerous sites.
Avast Free Antivirus
Avast Free Antivirus may not quite offer the best protection, then, but its interface is one of the best around, and experienced users will appreciate the program's extreme configurability.
Avira Free Antivirus
Avira Free Antivirus has a distinct shortage of bonus extras, which might be an issue for some. But still, Avira's stripped-back design is a plus, as it makes it easier to add other security tools without conflicts. Factor in its many configuration options and Avira is a smart choice for more experienced users.
Kaspersky Anti-Virus 2015 is a very thorough security package which offers multiple layers of protection to keep you safe from harm. Cloud-based technologies warn you about dangerous links or downloads, while an accurate antivirus engine detects and removes known threats as they appear. And if anything does manage to bypass your defences, Kaspersky's System Watcher detects dubious behaviour and can reverse many malicious actions.
Norton Security is more of a mini-security suite than an ordinary antivirus tool, combining antivirus, firewall, browsing protection, a password manager, identity theft and online browsing protection. One of Norton's strongest areas is in preventing you getting infected in the first place. An excellent URL blocker does a good job of keeping you away from malicious websites and the program won't allow you to run files it doesn't trust.