NOD32 all the way! Used to have Kaspersky before but after it failed to get rid my PC of some annoying popup ads which prevented me from playing online games by popping up like crazy over any window including that of the game, I installed NOD32 and it helped! I've been using NOD32 since then. My friend however is strongly convinced that Avast professional is as good as NOD32 and decided to use it because there is no need to search and input new keys. That's what he's told me today.