A couple of weeks ago, I gave you some of the top antivirus apps for your PC. The programs I listed were my picks for reliable free and shareware antivirus software that you could use right away.
Though having a good virus program is crucial to online safety, it's not enough to stop all intruders. Another extremely important line of defense is the software firewall. Some believe you need a hardware firewall (like as a function of your router, for example) to keep all intruders away from your system. But for most people (me included), a good software firewall offers plenty of protection against attacks and also against software on your hard drive that might be trying to contact "the mother ship" without your knowledge.
Like the antivirus programs I mentioned in the last article, software firewalls usually have a limited free version that works perfectly well on its own. If you want the extra features offered by the paid version like e-mail scanners, chat client security, pop-up blockers--in most cases--you'll have to pay for the full version. I've found that most of the extras are obtainable elsewhere for free. The bottom line is, having the free version of a firewall program and the added line of defense it provides is much better than having nothing at all. I strongly recommend that everyone that doesn't have a firewall at least get one of these software firewalls on their machine for the protection they give.
ZoneAlarm is one of the more well-known firewall programs, and it's the one I run at home. It installs easily and alerts you via a pop-up window the second anyone tries to access your connection?in or out. This way, you'll be able to designate safe apps and stop the ones that look questionable. A paid version of ZoneAlarm offers more options, but the free version is enough for basic security.
NetVeda Safety.Net is another solid firewall program which provides protection similar to ZoneAlarm. Like ZoneAlarm, this app lets you designate safe apps and keeps a close eye on what's trying to sneak through. My one problem with Safety Net is that some of the notifications can be pretty confusing unless you really know your stuff. This one might be geared more toward advanced users for that reason. You'll also have the ability to set parental controls with this app.
Comodo Firewall Pro is a recent discovery for me, but this pro version (with all the bells and whistles) is free for life. I like how this program analyzes regular application use to detect suspicious activity immediately. The smooth blue interface is easy to understand and each security alert comes with advice on how to proceed. Make sure to check out the developer's site (linked off of the CNET Download.com Comodo Firewall Pro product page) for tests you can use to check your own firewall for leaks before downloading this program.
The free version of each of these firewall programs offers plenty of protection for most users. If you don't already have a firewall through a business network or at home, I strongly suggest you download one of the programs above. If you've got a better firewall program, let me know in the comments!