With the advent of "always-on" high-speed Internet connections in small businesses, computers are under constant threat of attack. To protect your systems from viruses, spyware and other threats that can take up residence in your PC without your knowledge, you'll need a good firewall.

A firewall helps you protect your private business information. Some top ways it can help your business:

1. You can choose the information you want a firewall to protect, such as credit card numbers, passwords or banking information.
2. A firewall can prevent outside computers from accessing sensitive information, such as your address, while you and your employees are online.
3. A firewall can let you block "cookies" on a site by site basis. Cookies are small text files stored on your computer that help other sites remember when you revisit.
4. Firewalls let you know if anyone has tried to tap your systems.
5. A two-way firewall can help control outgoing information as well as incoming.

Action Steps
The best contacts and resources to help you get it done

Choose a dedicated firewall application

Make sure that the version you want runs on your PC, and look for an application that monitors both inbound and outbound traffic.

I recommend: Norton Internet Security is a top-of-the-line software bundle that includes firewall protection and can also protect your business against viruses, hackers, spyware and spam. Also check out PCMag.com's Firewall Security Software, TheFirewallGuide.com and ConsumerSearch.com's Firewalls guide. You can see more on PC security in PC World's "Bigger Threats, Better Defense."

Choose a free firewall application

Windows XP with Service Pack 2 comes with a basic built-in firewall, as does Mac OS X, but other free options are available.

I recommend: Check out the popular ZoneAlarm or others at Symantec. Freebyte's Guide to Free Anti-Virus Software.

Choose a firewall service

If you have a larger business with many PCs, you may want to choose a robust solution.

I recommend: McAfee and Symantec offer a wide range of computer security solutions for home office and small business. If you have a larger business with many Internet-connected PCs, you might want to hire an IT consultant to help you find the right managed service. Check out Geeks on Call or GeeksOnTime.

Get the right hardware

If you have an office network, consider a hardware-based firewall, which is typically found in broadband routers.

I recommend: Check out Webopedia.com's article "The Differences and Features of Hardware & Software Firewalls" for more details.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Never use two software firewalls at the same time; turn off the basic firewall that is built into Windows XP if you plan to install another firewall application.
• •  A firewall is only one part of the security you need on your PC — consider an all-in-one solution that includes antivirus, anti-spyware and anti-spam capabilities.