Er, I can only really give you advice if you're 
using Norton's Personal Firewall--if you're 
using something else I don't know the 
specifics.  For me, there's a little icon down 
in my system tray for the firewall.  When I want 
to turn it off, I just right click on it and 
choose disable.  Then when I'm done I right 
click again and enable it.

-Pasiphae