mrdevius,
Norton, AVG,McAfee, etc...these are aniti virus. They protect yoursystem from Viruses. (as long as you keep them updated).
Adware and spyware are a different type of 'invasion.' ...these you install yourself. (unknowingly)

As for Norton being poor choice...thats not true,...none of them are any better thatn the rest...they all have flaws. However...none of them protect you from adware/spyware.

I have tried most,...and I have been they luckiest with Norton.