In this hacker's mind, the online service failed to do a quality job in protecting children from online smut and as retaliation, he created and distributed a virus to as many file libraries of this service as he could. His intentions were to disable the computers of the online service's users so much that they wouldn't be able to connect for days. Calls may be free (1-800 or 1-877 number), or they may cost a small fee (1-900). 6. PC support groups or user groups are another option for help. These are groups that meet in libraries, computer stores, or other local areas and they discuss all sorts of issues related with a particular product. Even if you aren't experiencing a computer or software problem, user groups are fun to participate in and they can help you network into other interests such as job or teaching opportunities. That dot and group of three letters is known as an "extension," and the extension explains what kind of file it is. A file could be a plain text file, an image, a sound, a video, or program. But without seeing the extension, you wouldn't know it unless you double-clicked on it. The following list defines some of the most common extensions that you'll find on your computer. A firewall is software that checks all data entering and exiting a computer and it then blocks that which doesn't meet specified security criteria (user-defined rules).1 5. Don't click on website links in spam messages. In an effort to obtain personal information, some spammers will send email that asks you to click on a link. Conditions allow a program to perform an action based on the outcome of a previous command.3 Using this type of instruction, we could instruct a program to do one thing if the "x" variable in our latter example turned out to be 7 days, and then do different thing if the variable turned out to be 3 days. Using Computers It's Not Rocket Science These days it's strange to hear people say, "I'm just not computer literate," as computers have evolved from archaic scientific calculators to simple point-and-click type machines. We suspect that today's "computer illiterates" are people who haven't taken the time to experiment with such a machine.