What is the best free antivirus software? I have AVG and AVAST and AntiVir I don't think they need to be running at the same time but for I can't turn them off so I was wondering which one is the best of the three so I can just turn one one.

What is the best free antivirus software? I have AVG and AVAST and AntiVir

That is not a simple question to answer with confidence. Some reviews will suggest the following conclusion:

the best commercial AV products do indeed out-perform the best free products but the margin is not huge.

http://techsupportalert.com/free-vs-paid-av.htm

That can be a very misleading commendation and potentially dangerous strategy consideration since many test samples are often not current and most AV tools eventually address ALL serious infections within days of occurance (after the infection has already occurred). Also, 2 products with the same statistics may have very different characteristics - one may be highly weighted in very common infection items and the other in some more obscure items (conclusion - missing several or different more commonly occurring items). Free tools can also be less friendly to keep updated.


Your best comparison criteria is to Compare Proactive Detection rates (determined by testing very recent infection samples against each AV tool with three (3) month old virus definition signatures):

When new viruses, worms and other malicious attacks strike, traditional signature-based technology is insufficient. Every minute you wait for an update is another minute that your computer and network are vulnerable to damage, infection, or identity theft. ThreatSense Heuristics closes the window of vulnerability by safely identifying and stopping malware as it runs on your computer.

http://www.eset.com/products/compare..._detection.php

AVG and AVAST have been independently shown to be very poor in 'proactive detection' and against 'polymorphic viruses' (multi-version/mutating viruses) . AntiVir (AVIRA - free version?) scores in the top three (3) results if that is the exact tool (AntiVir PE Premium) that you are comparing:
http://www.av-comparatives.org/seite...R_June2006.pdf
http://www.av-comparatives.org/seite...se_2006_05.php
http://www.av-comparatives.org/seite...se_2006_08.php
http://www.av-comparatives.org/seiten/comparatives.html

Well Avira Personal Edition Classic picked up a trojan the other two did not but everytime I start XP it loads Avira, Avast, and AVG I only want to load one or maybe two but I get a message that Avira and Avast can't be running at the same time so Avast won't let me connect to AIM.

Well Avira Personal Edition Classic picked up a trojan the other two did not but everytime I start XP it loads Avira, Avast, and AVG I only want to load one or maybe two

You never want to have more that one real-time AV tool running at the same time to avoid conflicts and other issues. Uninstall or disable two (2) of those currently running tools.


It is not unusual for one tool to pick up a lesser known infection that some of the others won't (at least at that particular point in time). Also note: AV tools, overall, are generally poor against Trojans - better to use a dedicated Trojan scanner (s) or tool (s) like AVG Anti-spyware (previously known as EWIDO).



Reality Check and always the potential need for Second opinion scanning: http://www.virustotal.com/en/virustotalf.html

Check out the following to see the real state of AV protection for more obscure items:
http://www.virustotal.com/vt/en/esta...ction_failures

Blue: Infected files detected by all antivirus engines (less than 1%).
Red: Infected files not detected by at least one antivirus engine (more than 99%).