Symantic, McAfee and the rest of the "multi-box" packages are nothing but a pain. In my experience they suck up system resources and get in the way more often than not. They also tend to be expensive and, frankly, a bit too alarmist in their marketing tactics. Clearly some people think the free stuff from Microsoft is fine. I find it clunky, intrusive and a bit oblique. If they are asking me to stick to the "recommended settings" I would at least like to know why (and in plain English).
Microsoft includes troubleshooters that typically can't troubleshoot and an uninstaller that doesn't actually uninstall full programs. With that kind of track record, I don't feel very good about their firewall or anti-virus freebies. So, about a year ago, I went with Avast and have not looked back. It worked like a charm on my clunky old Dell (a piece if crap) and it's as wonderful on my new laptop (Toshiba Satellite, 8GB RAM, Core i5, Windows 7 64 bit). I also had my mother (a computer novice) dump Norton for Avast about six months ago and she loves it.
I started with the free edition and was impressed. It's also really free. Not a trial or a partial program. The user interface is very consumer friendly. It is very customizable so as you gain more experience you can play with more options. If you don't want to play, Avast covers all the bases and then some. I love the screen saver scan (which attaches a customized virus scan to your screensaver. Whenever your screensaver engages, so does your scan) as well as the targeted scans for email, USB devices, P2P downloads and Internet browsing. I liked the program so much, I switched to the paid version more out of guilt/appreciation than necessity.
Their online help is thorough and easy to navigate and understand. They are also very responsive to customer service inquiries. Avast Internet Security is about $50/year and it allows you to cover up to 3 PCs. It gives you anti-virus, firewall, anti-spam and an exhaustive array of network and Internet shields in one neat package. No matter what you choose, be sure that you are only running ONE firewall. Your Windows Security Center will summarize this for you. With Avast, turn off Windows Firewall but also check to see if your router if you are on a wireless network. Some wireless routers also come with a firewall.
Multiple firewalls running simultaneously can be a problem.