Fujitsu Netbook

Anti Virus Software Help!!!!?
So, I have the full version of Mcafee, the best one, my dad’s company gives all of its employees full unlimited subscription to it so it won’t expire.
However, I have recently heard of things like MIcrosoft security essentials and other free stuff.
Are those a replacement for a full blooded Anti-virus like Norton or my Mcafee?
Are they better?
Last question, I also have a netbook and a tiny fujitsu tablet PC, I use them less than my laptop and desktop, btw.
So, I am very annoyed when Mcafee cripples both of them using atom processors when running virus scans, even quick scans.
So would Microsoft security essentials be perfect in that regards? I heard it only takes 7mb of space too?
Please help, thank you
Microsoft Security Essentials is better than McAffe; however, Avast and Avg are not.
Panda might be your best option for virus protection on a netbook.
Hands on: Fujitsu MH330 Netbook