I've never really had a problem with Mcafee anti virus software since it is generally a pretty decent app that certainly seems relatively light on a host install. That is until now. People always accuse Microsoft of being all too legit and closed source which they are in many respects but it was only recently when I used my own USB stick on another system that had Mcafee anti-virus running on it did I realise that Microsoft's Security Essential was pretty chilled out despite the fact it detects everything including dodgy bits of software that aren't actually viruses but treats them as such because they don't really condone you having such utilities and programs.

Basically I had a program on my USB stick that I knew for a fact wasn't a virus. When security essentials picks it up it kinda' goes "Hey maan, I found this on your USB stick and I know you're not really supposed to have it and I don't condone the use of it which is why I'm classing it as a virus anyway, but I thought I best ask you first if you wanted me to delete it for you.. tsk-tsk".

Mcafee on the other hand was like "Hey you FUCKER! you're not supposed to have this and since its classed as a virus I'm not even going to ask you if you want to keep it or not and delete it on you just because I fucking can! Don't even bother trying to recover it using an advance data recovery program because it just won't be there no matter how hard you try, Ha! Loser!"

If I had to choose between Mcafee and Security Essential I would choose security essential.