So you should install a firewall on the computer that grants access to the computer, and then install an anti-virus and anti-spyware program on each of the remaining computers in the network. If you have files that shouldn't be shared (bank statements, credit card information, etc.), you can restrict their access in one of several ways. " Although these two activities are important, there's more you can do to extend the life of your computer beyond today's predicted two-year span. In fact, by following the simple advice below, you can enjoy the use of your computer to up to five years or more - reserving expenses to simple software upgrades rather then complete and costly hardware upgrades. Sit files don't install software - they merely archive a collection of them into one, or they significantly reduce the size of a larger one. Decompressing Files Assuming that you have Winzip or StuffIt installed on your computer, you can access the files archived inside a .zip or .sit file by simply double-clicking the archive (a file ending in a . This is almost unheard of in stores like Best Buy, Circuit City, or Egghead, yet the shareware programs offered within this price range rival even Microsoft's Office suite. Another advantage that shareware has over commercial software is its compatibility. We're not saying that shareware is compatible with all operating systems. One of the biggest problems that new computer users have with technical support is not knowing how to correctly describe the problem that they're having. And it isn't fair to expect a tech support person to automatically know what a "thing-a-ma-jingy," or "whatcha-ma-call-it" is. The following describes the correct names for common components of software so that when you experience a problem, you can effectively describe an issue that you're having and a technician can readily resolve it. The most important component of a computer's hardware system is its fan. The fan is located on the computer's CPU unit and when that thing gets clogged with dirt and dust, it can run down a computer faster than you can say, "Something's wrong with my computer and I don't know what it is!" In short, the fan is responsible for keeping a computer's motor cool and this motor is what keeps the computer's hard drive and peripherals functioning the way you need them to, which translates to "fast.