The front page of the interface displays a big advert for Avast’s paid-for Internet Security suite, and an ever-present “upgrade” button sits in the top-right corner of the window. Since it’s free, some advertising is inevitable. It’s easy to navigate, too, with a tabbed interface offering direct access to primary settings and information panes, and it’s illustrated with surprisingly tasteful graphics. In our view, the Avast Free Antivirus front-end is one of the most attractive around.