Firewall (re: Vista with Norton Antivirus)

Does Norton Antivirus provide a Firewall running on Vista? Where  is the control for this? And if I am using the Norton Firewall, should I turn off the Vista Firewall?

 

Reason for question: Ever since I dropped Norton 360 and installed Norton Antivirus, I have been having some crashes...especially at Shut Down. Plus, computer seems slow to open some websites. And I'm wondering if it is being caused by a Firewall conflict since I have the Vista Firewall "On."

 

Eric