Nicotine and tar mean certain death when it comes to computer fans, however should you find a need to clean the fan, do so with extreme care. It's quite easy to cause more damage from cleaning so if you're not comfortable with cleaning your PC yourself, take it to a shop for servicing. Otherwise, you can unplug and disassemble the computer to do it yourself. 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. All the drivers of a program are stored onto the computer and used whenever a program is started. Apple's Macintosh computer was among the first of a couple systems to establish a user-to-hardware relationship through a user-friendly interface. Today, we have quite a few operating systems. Some of the more popular ones are Windows Vista, Mac OS X, ZETA, IBM, Unix, and Linux. Instead of speaking to a human being, chances are that you spoke to a computer that not only responded to what you said and followed the commands that you gave it, it also asked you for more information such as your full name or credit card number. In this case, a person (such as yourself) operated a computer without even knowing it! Networking Home Computers Increasing Productivity With the Whole Family Have you ever thought about networking your computers at home? If you have a small collection of computers around the house (and a small collection of computer users), you can connect each one of those computers to one another and share data, software, and hardware including a single Internet connection. Viruses What They Are And One Reason Why People Make Them Over recent years, computers have become synonymous with viruses and viruses don't show any signs of disappearing any time soon. In recent news, LiveScience.com reported that "Before the month is even done, April has set a record for virus e-mails.