I would disagree a bit with the above post.
Yes, run only one firewall.
Yes, run only one ACTIVE antivirus and one malware and spyware program. However, it's perfectly alright to have additional protection programs which run only on demand, only when you initiate a scan of your system. No single antimalware/antispyware program will catch all the bad guys.
I gave up on Norton a number of years ago when it became BLOATware. It's too large and takes up to many system resources. The three primary protection programs I use are, AVAST antivirus (always active), Malwarebytes antimalware (Demand only), and Superantispyware (Demand only). All are free. My system is pretty clean.