I was virus free for 3 years, then got hit by a new generation of the zeroaccess rootkit about 6 months ago. I literally got hit, saw something funkky was going on and disconnected from the web, pulled open my phone and found an article about zeroacces.gen.b or something like that written 2 hours earlier. That ruined my week
On the bright side, i had a lot of fun messing around in the registry fixing it and learning my way around the registry and some of the .dll files on win 7 as well as services, processes, and some tools in the default install I didn't even know existed. Then I wiped my HDD and did a clean install just to be safe lol ^_^
As for windows essential, i would avoid it. Windows has bugs, period. All of their software has problems with being vulnerable over and over again, it may not be their fault as its entirely possible every program has flaws but since windows are the only ones gauranteed to be on most installs out there malware coders focus their efforts on default and commonly used windows programs but thats another subject to debate, but historically speaking your odds are going to be higher for failure if you use a windows AV. Simply because of the number of flaws windows products have had/do have.
I personally am a HUGE proponent of Bitdefender, though I heard they went from 30 a month to 60
But for free options, Panda cloud antivirus is amazing though its still in beta. It catches all the infections, just doesnt remove them all. So id say go Panda, then run malwarebytes periodically and you should be okay.
edit*
is proponent even the right word to use there? this doesn't happen often, but I'm doubting my english 0.o
