There are plenty of free anti-virus programs available such as Avast, AVG, BitDefender or Comodo however the below list mentions some of the light weight free anti-virus programs that requires less space & less memory and does not slow down your computer.
ZenOK antivirus is free full featured ultra-light security application that scan files in real-time, gives online protection, anti-spyware,anti-adware, anti online banking trojan features and uses 0.1% of your system resources. It also provide online data backup. The app has got beautiful & colorful interface and at the same time effective protection for your computer.
ESET for home users is a lightweight and hassle-free internet security solution for your system with features of antivirus, antispyware, firewall, anti-rootkit and antispam capabilities, its uses ‘cloud‘ power which means that virus signature files are stored in the clouds and not on individual users computer machines. It has multiple layers of detection to keep out threats and block all potential vulnerabilities while you engage in work, social networking, play online games or exchange data via removable devices etc.
ESET also have other free security and antivirus tools for downloads such as ESET NOD32 Antivirus, Cybersecurity, NOD32 Antivirus for Linux Desktop and for mobile security you can find them all here.
DigitalDefender free version is also ultra light weight, easy to use, extremely fast, gives real-time protection and a anti-virus program that never slow down your computer. The program is designed for both beginner and experienced computer users thus GUI of DigitalDefender is very easy to use, simple & minimalist.
DigitalDefender supports Windows 7, Vista and XP and it is free for non-commercial users i.e. for home users only.
ZoneAlarm is a completly free anti-virus software with no trial period. Available for Windows 10/8/7, Vista and XP users, it guard your PCs/ laptops against viruses, malware, spyware and even hackers. Some of its notable features are — Personal Firewall, which makes your PC invisible to hackers and protects your data from being compromised, Identity Protection, which send you daily credit monitoring to help protect you against identity theft and guard your information from hackers, and Automated online backups, which restore your files and data in the event of loss, theft, accidental deletion or disk failure.
Microsoft Security Essentials is a free anti-virus program for Windows vista/7 users and to guard their PCs/ laptops against viruses, spyware, and other harmful software. It provides real-time protection with auto updates & scan features for your home or small business systems.
MSE is available for small businesses with up to 10 PCs and if you exceed this figure, you can have protection with Microsoft System Center 2012 Endpoint Protection, which is a paid version however after few days of free trial .
If you are looking for best basic protection for your PC that eats less of you PCs RAM & system resource than this is one of the best entry-level antivirus software that eliminates many forms of malware, virus,worms, trojans, rootkits etc in minimum user intervention yet manage vulnerabilities effectively. Apart from free version even its premium version which is paid is worth buying at very cheap price of just USD $17 approx. (873 INR). Its one of the best antivirus software in terms of ease of use and fast scans for free version and value-for-money for premium version.
Zillya free version of Antivirus is also light weight and gives real-time check of files and mail messages, it also protect its users from harmful malicious websites by blocking user from accessing them. It has simple and user friendly interface.
Zillya uses Unique Heuristic Algorithms which actually uses typical malware behavior patters to detect new and unknown malware that was not yet processed by virus lab and yet to be added to virus database, this helps program to deal with the newest variants of malware.
ClamWin is an Open Source free antivirus & security program for all Windows platform, it comes with an easy installer and open source code under GPL (General Public License) and offers high detection rates for viruses and spyware, standalone virus scanner and an add-in for Outlook mail attachment virus scan.
However, disadvantage of using ClamWin as Free Antivirus is that it is not recognized by Windows Security Centre as it does not scan files automatically (that is when you access or open a file), you need to scan a suspicious file manually before opening it. On other hand if you use MS Outlook email client (not Outlook Express) then all emails are scanned automatically when you open them.
Immunet (Free version) is also a cloud-powered free community-driven antivirus application powered by open source ClamAV engine designed for detecting trojans, viruses, malware and other malicious threats. Immunet is small and take less space on disk (~10MB ) unlike to other antiVirus software and its fast, free, offers up-to-date protection against thousands of new threats on daily basis. Being community driven antivirus means – once a virus is detected and blocked for one user, all other Immunet users receive the same protection, almost instantly.
In year 2011 Immunet has been acquired by Sourcefire, a network security hardware and software.
[Last Updated – 15 April 2017 ]