Hi, Initially, sorry about my english. A lot of people say: "Don't check "advanced heuristics" and "runtime packers" - your system will decrease performance". Others posts say: "Advanced heuristics is the most important feature of nod v3, don't uncheck it" But, nobody knows a parameter for this?! Which computers will really decrease performance?! Example: I put v3 on my computer these days...I have a dual core 2.0 with 1 gb ddr 800. I don't saw any decrease with this options marked, but, in the future, can I have a slow system because this options?! And more questions: Decrease performance = another weighty AV?! Or like of kapersky? (not weight but not light like nod) v3 with "HA" and "runtime packers" unchecked still is better than v2.7 or the same thing?! My mother's computer is a p3 550 with 256mb and nod v.2.7 - It's a old computer, but, works fine for her - Should I change to V3?! I think that I should, but I get frightened of being very slow. Sorry about many questions.