Shoutbox

Do you have a NAT'ting router?

internet -> ISP device -> NAT router -> your PC

By security suite are you referring to 'software firewall' + some other junk?  Or are you asking about HIPS (Host Intrusion Prevention System)

NAT per se isn't a firewall, but it should be protection enough for you.  To properly use a software firewall you're going to need to understand lots of new things, and since you're not using one now, vicious circle, you're probably not ready to go there.  Especially if you're not running any public services on your machine.

If you're hell bent on a software firewall for the love of sanity STAY AWAY from Zone Alarm.  The tards fond of it also think overclocking is a great idea.  Outpost is where it's at.  Find some reviews.  Don't trust overclocking sites or anyone who endorses it

You should really start researching HIPS first