Again, unless Thorn's got a giant office with a bunch of employees now, an expensive 3rd party firewall is absolutely unnecessary. Windows software has a built in firewall that's good enough for most offices.
When You Would Want a Third-Party FirewallBy default, the Windows firewall only does what’s really important: block incoming connections. It has some more advanced features, but they’re in a hidden, harder-to-use interface.
For example, most third-party firewalls allow you to easily control which applications on your computer can connect to the Internet. They’ll pop up a box when an application first initiates an outgoing connection. This allows you to control which applications on your computer can access the Internet, blocking certain applications from connecting.
Power users may love this feature, but it’s probably not a good feature for the average user. They’ll be charged with identifying applications that should be allowed to connect and may block background-updater processes from connecting, preventing their software from updating and leaving it vulnerable. It’s also a very noisy task, as you’ll have to confirm a prompt box every time a new application wants to connect. If you really don’t trust a program to connect to the Internet, perhaps you shouldn’t be running the program on your computer in the first place.
Nevertheless, if you want outgoing-connection management, you’ll probably want a third-party firewall. They also offer an interface where you can more easily view statistics, firewall logs, and other information.
For most users, using a third-party firewall just introduces unnecessary complexity.