I used to use Bullguard.

I am supposed to be entitled to 3 licenses.

However when I changed laptops, I found out I could not access my extra licenses.

What happened?

I am temporarily using Avast 2011. It looks good enough but the fact that I downloaded free is not exactly comforting.

How good is Avast?

What really is the difference between free anti-virus and a paid one?

Many questions.

But I know the techies on NL are always on point.

Thanks guys.

there are some locked functions that is not allowed on free antivirus but you get them immediacy you upgrade to full version

To add to what folafola has said, when you use free version of an antivirus, there are some features of that antivirus that you wouldn`t be able to use but when you now buy the license key for the antivirus, all the features of that antivirus would now be available for you to enjoy. Including option for you to update the antivirus once you are connected to the internet (in order for your antivirus to be able to detect latest virus codes) which most free versions of antivirus might not give you opportunity of.

folafola: there are some locked functions that is not allowed on free antivirus but you get them immediacy you upgrade to full version

he have said it all ........

Well, using Avast as an example cos I use both the free version and the paid.
In Avast free: You can only do virus definitions update

Avast pro: Gives you firewall protection as well as virus difinitions update(its a paid version as well

Avast internet security(AIS): Possesses all the features you have in both free and pro version.
I.e definition updates, firewall,internet security etc