We use AVG free version at home and I use the AVG pro version at work.

When navigating their site, it was a little confusing trying to locate the free version - probably intentional. Grisoft is the software publisher. You may need to go to the "grisoft" site rather than a site with "avg" in the web address. That's the way it was set up the last time I downloaded a free version.

edit- nevermind, see poppachub's post for link.