On my system is one of the most light antivirus. But here many persons found KFA light and on my system is heavy. Especialy boot time need i day to open my laptop.Whatever computer I tried Avira on, it always brought it to its knees. Its detection might be great, but it is the heaviest AV I know, even worse than WD. I do not understand, how can it excel on other computers, but I guess, there are other variables involved. I never recommend it, rather Adaware.