Many home users have unknowingly become computer geeks. Not too long ago using the terms 'router' or 'wireless' signaled the presence of the enthusiast or professional. No longer. Now, routers, hubs, switches, Ethernet cards, firewalls and a bewildering array of other network related buzzwords have entered the home.

Personal firewalls offer a selection of protection levels depending on whether they're connecting to a private network or the Internet. Computers in a home network, for example, will usually be allowed to share files and access common resources like printers without restriction. In this case, the firewall will allow more access than when connecting to the Internet.

Fighting spam — like countering any illegitimate activity — is a battle fought best on multiple fronts. There are simple steps end-users can take to minimize the impact of junk mail (outlined in Part I), but the webmaster or e-mail provider has even more tools available.

Most people are familiar with the legend of the Trojan horse. During the siege of Troy, the Greeks left a large wooden horse outside the gates, allegedly as a peace offering. The Trojans brought the horse inside the city walls only to discover it was full of Greek soldiers who quickly sacked the city.

E-mail has become an essential mode of communication in the modern world. Unfortunately, that means it's also one of the most common routes for virus infection and fraud. Protecting yourself from these kinds of threats is necessary for everyone.

Fighting spam - like countering any illegitimate activity - is a never-ending battle. You devise a strategy and there's a counter-response. But taking low-effort steps that make spammers actions ineffective or difficult puts you at an advantage.

For many people, computers have become a daily necessity. We use them for work, for correspondence and for entertainment. Many of the files are important documents and losing them would cost us time and money. Backups are the best way to prevent their permanent loss.

Along with spam advertisements hawking prescription medicines, 'cheap' mortgage rates and online gambling sites, there are a number of common scams whose sole goal is to separate you from your money.

Spyware can be more than an annoyance. Poorly programmed spyware can interfere with other programs and can even cause system instability. Privacy issues are at stake as well.