Whenever I try to get AVG Anti-Virus Free, it only directs me to a link to upgrade from 7.1 to 7.5. Since I had 7.1 removed from my machine, this upgrade obviously will not work. But I can never find a link to the actual 7.5 install itself. Does this even exist? How does one find it? Or better yet, is there a better free anti-virus option available?