Tip 2: "Erect an Armor of Fire"

Install and enable personal firewall

You can use a personal firewall to keep hackers away from your PC.

Some operating systems, such as Microsoft Windows 7, Mac OSX and Redhat Desktop, already come with basic personal firewall features. You can also acquire a personal firewall software package from security software vendors.

Most personal firewalls work fine right out of the box. When you initially run a firewall, it asks you which applications you want to grant access to the outside world through the network. Most personal firewalls can save your selections, so that they will not prompt you again for the same application. Once this initial configuration has been set up, your PC is protected by the personal firewall.

Block all unknown traffic

To effectively protect your PC from unauthorised access, personal firewalls may handle network traffic in three different ways according to their characteristics:

• Allow: the firewall allows network traffic to flow through if the traffic is considered safe to your PC. This traffic is usually generated by applications you have permitted to access network resources during the initial configuration.
  
• Block: the firewall blocks traffic if the traffic is considered unsafe to your PC.
  
• Ask: when the firewall detects suspicious traffic, it will alert you and ask for your instructions. You may either allow or block the traffic. Bear in mind that you should make this decision with care.

The first principle for responding to firewall alerts is that you shouldn't let any unrecognised traffic pass through the firewall. In general, you may allow some common applications that need access to the network such as Microsoft Outlook and Internet Explorer etc. If an unknown application tries to access network resources, it is better to block it first. You can change your decision anytime when you confirmed the application is genuine and necessary.