Since some people in this thread have convenient eyesight for low memory footprint,then let me ask which av uses around 4mb's or less,well i know for a fact webroot uses 4mb.
Well the WSA do use 4mb and less, but if you tend to install lots of programs for testing its recovery folder can occupy more than few gb's of hdd space. Than again to talk about memory footprint in this age is pointless. Memory occupation is not the same as system speed impact. Most of anti malware industry have great products (little to no variations) and most of them protects us from our bad routines/habits. In the end what differs one from the another (in top category) is our own preferences/imagination/affiliation.
If someone want one best solution ... try the church
We, on MT, have discussed a countless times already that the RAM usage is probably the less important thing for an AV to system impact.
But there was no such question here on this topic...
And, yes, again, there are AV's that uses less than 10mb of RAM
RAM usage is not very important for me, since these days most computer have 2Gb (minimal) or more, except your computer have 512Mb then it should be something you really need to think about
But speaking about AV that use very less memory, according my experience Webroot is the lightest.