Eset NOD antivirus this antivirus I installed in my computer when I did not have any antivirus and my system was not performing well .it became slow or perform slow when we open multiple window or multiple application at a time.i took it from one of my friend and installed it.once installation done it automatically detected many firmware and some malicious code and lots of more which installed in my system which I don know.it may not slow your system and automatically switch to game mode when we play game.it does not affect any application and updation is available it might ask you to update your antivirus because virus is made day by day and upddation is needed to prevent from those virus.