Firewalls are very important for everyone to keep your system safe from malicious users. If you do not connect your machine to the Internet then you need not think about Firewalls. But I know many people will connect to the Internet. So everyone needs a Firewall to defend from malicious attacks. When it comes to security I prefer UNIX to Windows. My windows machine is always infected with viruses. But my UNIX machine is very robust in this area. But the problem is that I don’t get much software’s for my Linux machine. So mostly I’ll be using my windows OS even it causes many problems.