Firewalls
Firewalls are a must for todays users. They can mean the difference between a user’s sanity and insanity. Leaving a computer with out a firewall is equivalent to leaving your front door wide open with a neon sign reading “Have lots of cash – no dog” at night in Newark. Not a good idea.
Unfortunately free firewalls are disappearing rapidly.
There used to be at least three good free firewalls – Tiny personal firewall, Sygate firewall, and Zone Alarm. Now of those three only Zone Alarm remains free. There is also the built in Windows Firewall. The built in firewall is better than nothing but it is not as good as Zone Alarm.
The free version of Zone Alarm has some drawbacks. For example you can not open specific ports. The firewall controls access based on applications. This is fine for most home users but can be VERY annoying to more advanced users. If you need this level of functionality you have got to go commercial.
You can download Zone Alarm from: http://www.zonelabs.com/store/content/company/products/znalm/freeDownload.jsp?dc=12bms&ctry=US&lang=en