best antivirus for PC

A few days ago I met in the street a university student, I asked him what he was doing the work, it is because we have little contact after graduation, so the other side of the situation is that I do not understand ah! I am also very depressed, when I asked my students, he told me that he is now in the computer city to work, but also told me that if I home computer have any questions, let me direct past to find him on the line, I heard after it bluntly said the situation in my home computer, he immediately said that it is determined to give the best antivirus for PC computer to install it, but I also do not ah! So I think this weekend with my laptop to look for him, so he gave me the computer to install best antivirus for PC, the way to see him.