Free AntiVirus Software Utilities PC Tools Antivirus Free Edition PCTools Antivirus Free Edition protects against a variety of malware, including viruses, worms, and Trojans. It provides real time scanning of the files you execute as well as the email you download. (Scroll down the linked page to find the free edition.) The commercial full version of PC Tools Antivirus (download trial version here) also provides speedy antivirus definition updates (to provide timely protection against viruses). The program supports Windows Vista, XP and 2000 only. Comodo AntivirusComodo Antivirus provides real-time scanning, where it resides in memory and checks your programs for viruses as they are run, as well as on-demand scanning for viruses. You can also schedule your scans. It automatically updates itself through the internet. Note that you have to activate your copy as well as supply your email address to get and use this software. This is a Windows program. Clam AntiVirusClamAV is a free command line antivirus scanner for Unix systems. You can also integrate it with your mail server for scanning your email messages and attachments. It is able to scan inside archives like RAR archives, Zip archives, Gzip and Bzip2 archives (that is, it has unpacking engines for those types of compressed archives). If you are a programmer, you can even integrate the antivirus scanner into your own programs. This free antivirus program comes with source code that is released under the GNU General Public License. Prebuilt binary packages are available for numerous Linux distributions (Debian, RedHat / Fedora, PLD Linux, Mandrake), Microsoft Windows, FreeBSD, OpenBSD, AIX, OSF and Solaris 8 (Sparc). AntiVir Personal EditionAntiVir Personal Edition is a free antivirus program for Windows computers. It has a resident component that monitors file movements for signs of viruses. It also allows you to scan your computer and repair files that have been infected. The program comes with a facility to automatically check the AntiVir website for updates to the virus definitions and download them. Updates are free. AVG Anti-VirusThe AVG Anti-Virus software comprises a resident program that works in the background, an email scanner (checks your email for viruses), an on-demand scanner (eg, you invoke it to scan your system), the ability to repair certain infected files, and automatic updates of the virus definitions. A more fully featured commercial version, AVG Anti-Malware is also available. The commercial version not only protects against viruses, but also spyware and other malware. F-Prot Antivirus for Linux, FreeBSD, OpenBSD, NetBSD and DOSF-Prot Antivirus for DOS, Linux and BSD (FreeBSD, OpenBSD and NetBSD) is free for personal use on personal workstations. (Note: these are separate downloads; scroll down on their page to find the link appropriate for your system. Also note that the Windows and Solaris versions are not free.) avast! Home Editionavast! Home Edition is free for home users on non-commercial computers. You have to register your copy and supply them your email address (get a free email address here if you wish) so that they can send you a license key to activate the program. Free Online Virus Scan Freedom Free Virus ScanThe free online virus scan from Freedom Internet Security and Privacy scans your hard disk, diskettes, CD-ROMs, network drives, directories and specific files for viruses, Trojans and worms. Jotti’s Online Malware ScanThis site scans any file that you upload to it with a variety of antivirus programs. It is particularly useful if you are suspicious about a particular file, and want to see if different antivirus software detect anything in it. BitDefender Free Online Virus ScanThis free online virus scanning service will check your system for viruses. Note that the service only works if you use Internet Explorer on Windows since it uses ActiveX controls to do the scanning. Alternatively, you can buy their software product, BitDefender Antivirus, which will allow you to protect your computer from virus, rootkits and malware threats. Trend Micro Free Online Virus ScanScan your computer for viruses free with Trend Micro’s online service. You will need either Netscape (3.01 or above) or Internet Explorer (4.0 or above). The European version of this service supports Internet Explorer, Firefox and the Mozilla browser only.he computer security market is flooded with antivirus software that work but don’t come cheap.

While viruses remain a threat to our precious data, you need not necessarily invest in expensive antivirus scanners - there are plenty of free options available that may give even some commercial vendors a run for their money.

We look at some of the best software available today for keeping your computer free of viruses and other malware. Later we help you decide the one most suitable for you.

Free Online Virus Scanners [run inside the web browser to scan your hard drive]

Trend Micro HouseCall - An online virus scanner that’s absolutely free and scans your PC hard drive for any sort of viruses or even spyware. HouseCall allows you to remove detected infections. Works with Firefox and IE. Requires Java.

McAfee Freescan - This free virus scanner from McAfee is based on the McAfee VirusScan engine. Should viruses be found, FreeScan prepares a list of infected files and links to information about the viruses on your computer. It also gives you an option to clean your system. Requires IE with ActiveX.

Windows Live OneCare Scanner - A free antivirus online scanner from Microsoft that cleans your system from viruses and also recommends ways to improve the overall performance. Part of Windows Onecare.

Symantec Internet Security - An online virus scanner from the developers of Norton Antivirus 2007 can detect most virus threat but there is no option to delete the virus infected file or repair it. Does not examine compressed files. Requires IE with ActiveX.

BitDefender Online Scanner - Their Free Online Virus Scanner version 8 scans your system’s memory, all files, folders and drives’ boot sectors - the default options automatically cleans the infected files. Requires IE with ActiveX.

Free Anti Virus Software for Windows [Requires Installation]

Avast! Home Edition - One of the most popular antivirus software, can also be run from Explorer context menu. You can either scan the entire hard drive or selected folders. Ships with an Antivirus screen-saver.

AOL Active Virus - a free virus scanner from AOL based on Kaspersky Antivirus that doesn’t require an AOL account to download the software. The software can be configure to check only new and modified files thereby reducing the memory requirements. Also support scanning of incoming and outgoing email messages.

ClamWin Virus Scanner - An opensource antivirus software that is great for running routine antivirus checks on your PC. You need to manually scan a file in order to detect a virus or spyware.

AVG 7.5 Free Antivirus - One of most popular free virus scanning software is AVG 7.5 Free Edition (read comments). Initially, there was confusion whether AVG 7.5 would be free like AVG 7.1 but the good news is that AVG 7.5 Free edition is already available for non-commercial, single home computer use.

Conclusion: Which one should I choose ?

Unlike Desktop antivirus software, online virus scanners do not proactively protect your PC against new virus infections.

But if viruses have already entered your hard drive and taken control of your existing desktop scanner program, any of the above listed online virus-scanning services can save your day.

If you are a fairly experienced web user who doesn’t need an antivirus software to run in the background 24 hours, scan you drive at regular intervals using HouseCall. Others may install the AOL antivirus software which uses the Kaspersky virus definitions database.