For the last three or four years, I have not been using any anti-virus software in any of my machines at home. We have two laptops and a few desktops all of which are continuously connected to the internet. Both me and Shobha are very active internet users. Our primary communication mode is email and instant messaging. But, after Vista/XP SP2, we made a decision that the cost of licensing an antivirus software and performance penalty that it causes is not worth the protection it provides. Furthermore, we are the only people who use the computer. In the last 20 years or so that we have been using computers, we believe that we have enough behavioral protection against malicious programs and social engineering kind of attacks. My primary browser is still IE (8).
I used to have both Symantec and McAffe antivirus thingies. I also tried a couple of freeware versions as well. The first two are extremely intrusive and makes all sorts of issues during normal operation. It was impossible to run such intrusive and resource hungry background processes in my Audio Workstation. The same with Shobha with her graphic workstations.
Today, just for the heck of it, i downloaded and installed MS Security Essentials. I have been reading about it from the beta stage. The reviews of it were not all positive as we know. But the overall rating was that it is not too far behind in detecting malware. A lot of people praised its small footprint and conservative resource usages. So, installed it and ran a full check of the system. Of course it used between 20-40% of the processor (one core) but very low memory footprint (50MB during full scan with UI open). As I expected, it did not find any malware. So, after 3 years of 12-16 hours of online exposure without any “security” other than my common sense and the basic protection provided by the OS and browser.
I already turned off the live protection. In a few days I will eventually uninstall it as well.