[Jeordiewhite]

Well hardware firewalls are usually better, in this case it is a hardware firewall(more secure than a software firewall, however no program control except in this case it can). I'd install them both as you shouldn't notice the difference in a software one on top of it for program control. However service pack 2 has program control(limmited) with it's firewall, mainly asks for server rights, i.e. for online games etc. Why I mention the windows firewall, contrary to what implexant said, nvidia's nv net firewall is controlled by the Microsoft Windows firewall to configure the firewall. I found most people said you could not configure the windows firewall to work with file sharing programs or such as an ftp. This is incorrect, I entered in the proper settings to the firewall to see if i could allow an ftp or such. It worked just fine if you know how to enter port settings.
I've used zone alarm ontop of the windows firewall just for testing, zone alarm disables it but can be changed, works just fine.
If you have a router with a hardware firewall, then it's not personally needed, but if not then try nvidia's firewall to see how you like it anyhow, with a router etc, i wouldn't use both a software firewall and nvidia's.