All recent versions of Windows come with a built-in firewall and, whilst it's perfectly okay to leave your PC with this thin layer of protection, before long you will want something that covers a little more than just the basics.
Thankfully an industry has grown out of providing this type of software and the amount of competition means that there are plenty of programs to choose from.
1. ZoneAlarm Free Firewall
Those of you looking for a firewall, antivirus software and identity protection all in one easy-to-use program will immediately be impressed by the ZoneAlarm Free security suite.
Its centrepiece is a two-way firewall that makes your PC invisible to malicious hackers whilst at the same time preventing spyware from sending any data online that it may have pilfered from your Windows PC.
Another strand to the firewall is that it monitors all programs on your PC for suspicious or out-of-the-ordinary behaviour and alerts you to anything untoward whilst preventing new attacks that are designed to get around traditional anti-virus programs.
2. Comodo Firewall
Comodo Firewall takes a slightly different approach to ZoneAlarm in that it genuinely feels like Comodo is attempting to take over your computer - in a good way of course - and it's surprising just how many features it has for a free program.
A small box runs in the top corner of the screen that keeps a constant watch on the traffic running to and from your system and the program offers five main icons that allow you to scan, update, run a virtual desktop, quarantine threats or speak to live support for even more help.
The Firewall settings are extensive and let you to permit and block applications that want to connect to the internet, manage your PC's visibility to other PCs, allow or block internet connections and block all network activity.
Blocking certain IP addresses is a big part of a firewall's remit and PeerBlock is the best program out there at doing that, and only that. In this sense PeerBlock is very simple yet it will keep you out of trouble without the flashy appearance and memory draining effect that some fully-fledged firewall/anti-virus programs have.
Off all the firewalls on this list, Privatefirewall is a minuscule-sized installation that performs the job to the same level. Another in the no frills camp, it is just a firewall plain and simple with a main menu that shows the status of the firewall (i.e. whether it is on or off), a selection of different profiles depending on location, and a list of sites that are trusted or blocked.
Gone is Comodo's annoying tendency to ask you about every single thing. Privatefirewall instead works to understand how you use your computer and then allows regular programs to bypass the process while it tracks down threats.
5. Anti NetCut 3
Another specialist program, Anti NetCut 3 attempts to stop programs from accessing your internet connection by protecting the network adapter connected to your PC. It works largely in the background after the initial setup and looks out for any attackers attempting to cut or manipulate your connection to the internet.
If it detects anything it gives you a warning and then kicks off an anti-spoofing technique that protects your network connection and ensures that your online privacy is 100 percent protected.