text: dose avast slow your computer down?   yes. avg slows down our computer because it would tempt to open up a popup beside the taskbar to inform us that we have a virus detected. that popup is heavy duty unlike with norton antivirus which is simple and lighweight to use. other than slowing down our pc, it can't even protect us from newly created viruses such as brontoks. they are not providing real-time virus definition updates. but if you prefer a free antivirus software then avast is your choice :)