Now, the fact that my router/switch being a firewall honestly didn't even occur to me but you're right; with NAT and SPI I guess I don't need another firewall, especially a software firewall.
But honestly, even with the firewall built in to the router there have been times in the past when AVG has alerted me to a suspected intrusion. I haven't had that happen lately, though, like in the past year or so.
I guess I need to re-evaluate my network and adjust accordingly. I have a Netgear WG614 Wireless Router with NAT and SPI and DoS attack protection. In your honest and humble opinion, do I still need a software firewall?
IMH&HO, No. The Windows firewall suffices. I believe it was in XP SP1 that they redesigned the Windows firewall and made it secure. I think anything else is redundant and you end up paying for something that you already have. So you already have two lines of defense. The router is the first firewall and the Windows firewall is behind that. Between them you’ve got a pretty good defense.
Keep in mind that no matter how good your defense is, if you click “OK” or “Check My System” or anything like that when something pops up on the web and tells you your system is in danger and needs to be scanned, you just did away with any defense you have and gave permission to the intruder to do whatever it pleases. But I think you probably already know that.