In his mind, the loss of connection meant loss of revenue for the online service. Although the malicious code that this person generated may have worked for a small percentage of users, sufficed to say, the online service continued on and still exists today. Despite his motivation or intention, his efforts were null. Since we're describing a home network that will connect to the Internet, you're strongly advised to install a protective firewall program to thwart Internet viruses, worms, or other damaging spyware code. Firewalls prevent - but they don't repair. Only anti-virus and anti-spyware programs can reverse damage. Some of the most common parts of a menu bar grants access to File commands, Open commands, Save commands, and Print commands. An example of an error in this part of an interface would be if an option was missing or grayed out (lighter in color). Tool bar - this part of a program displays small icons across the top which represent tools. " A dirty fan doesn't rotate fast enough to keep that motor cool and a completely clogged fan just stops rotating altogether. This causes the computer's motor to work harder - and a harder working motor can raise the electric bill! Worst case scenario: the motor can overheat and stop working as well. ) is protected from prying viruses or hackers, while the newer machine is used to surf the net. As you can see, old computers still serve a purpose either for you or for someone else. And although selling an old computer is always an option, there are a number of things that you can do with an old computer. If you're familiar with MS-DOS at all, you'll recall that it's a command-driven operating system that performs functions issued at the C:> prompt. The only way to get an MS-DOS computer to do something was to type a command at this prompt and if you can imagine, it was a rather cumbersome way to use a computer.