I am asked all the time which anti-virus software I prefer. I tell folks to pick one, it really does not matter. I am serious. AV software is a commodity today, and they all do the job. We can have a debate over which one perhaps has less of a performance impact, or which vendor is the first to release a new virus update, or even which one is cheaper. These are all good points to debate, but it would only be an opinion and someone else would come along with a better argument. Let's get over it and agree that the top vendors -- AVG, CA, Symantec, McAfee, Kaspersky, BitDefender, WebRoot, ESET, Trend Micro, and Sophos -- (these are not in any order, mind you) all do a good job at defending us against viruses, worms, malware, and whatever else you want to throw in here.
Microsoft will be taking AV software to a new level of commoditization by putting into the cloud. Its new AV software, first code-named Morro, after a beach in Brazil, and now named Microsoft Security Essentials, will be free in an attempt by Microsoft to shake up the big two AV vendors, Symantec and McAfee and take business away. I do see a catch, though. If you sign up for the service, all of your Internet traffic will be sent through a Microsoft data center. There, the application will inspect and block suspicious malware in real time. Microsoft has been working on this for some time now. I believe that it needs to work out how it's going to reroute that much traffic without a performance impact.
If your AV software is not doing a good job at protecting your systems, dump it and get another. There are too many to choose from that do what they are designed to do. Don't get tied to an AV vendor. Switching AV software is not like switching an operating system. There should be a fairly short testing cycle with little impact to your applications and network.