Am I secure? oO

Right so I'm wondering if I'm secure on the internets, I'm using FF with adblock+noscript and WOT for when I'm randomly searching for worthless shit on Google, also using Avast Antivirus Pro, Comodo Firewall, S&D and Malwarebytes' Antimalware (Licensed).

So how secure is my PC? :P

You'll never know.. could always be a zero-day exploit out.. question is rather, how important is it to you?

For example you could set up a Virtualbox running Linux with non-persistant virtual disk so it gets wiped every time. Combine this with a shared folder to your real OS for downloads and you're running extremely secure.. but is that really worth it?