Firewall and Antivirius?

I have a home PC and it has 2 firewalls and 2 antivirus softwares. One is from McAfee Security Center, which came with my PC when I purchased it (it has since been updated 2x). The other is Norton Protection Center, which was included with my Internet provider's do-it-yourself installation kit.

Now, both of them have firewalls, I've already turned off the Norton firewall and left the McAfee firewall on. My question is should I keep the both antivirius softwares on or turn one of them off? Also, what's the benefit of not have 2 firewalls and 2 antivirius softwares running at the same time?

Thanks in advance

Firewall and Antivirius?anti virus scan

it is recommended that you only run one antivirus and one firwall at a time because they can and do conflict with each other causing your system to run slow or even freeze up;

SG

Firewall and Antivirius?ariel

DON'T have two firewalls running at the same time and DON'T have two anti-virus programs running at the same time. Very likely they will clash with one another and make your 'protection' void.
A firewall is a program that sits in between you and the internet, it analyses incoming and outgoing traffic to try to intercept threats to your security. It's mainly looking for hacking attempts. As long as your internet connection is open its like an open door to hackers. A good firewall will make your pc invisible to most hackers. If they can't see you they can't break in.