So how good is Norton?...(uber n00b here alert)

Yes I even used 0s when spelling n00b. That's how hardcore I am.

I recently got a laptop for Christmas (woo) and my parents also bought me Norton Anti-virus with it. I was delighted (ahem) to see that Norton was already on with a 60 day free trial.
Reports on Norton that I have heard have been...well mixed to be fair....the biggest complaint being that it seriously reduces your Laptop's speed.

Should I get a different one like McAfee? Or are the rumours of a very good and free anti-virus programme knocking around on the net true?

I appreciate all your help. I am not technollogically incompetant (or however you spell it) but also not amazingly knowledgeable about the subject so any help people can offer would be awesome.



Thanks.