Anti-virus/anti-spyware software will stop malicious code from downloading and installing onto your computer while you peruse the Internet. Known as viruses, worms, or spyware, this malicious code can destroy important files and render your computer good for only one thing: sending sensitive data back to the server of an identity thief. This will decrease the time it takes for your computer to send it elsewhere, and it will also decrease the time it takes for someone else to download it. To create your own .zip or .sit file, you can select a single file or a group of files from within Explorer, and right-click the selection. Again, depending on how you installed Winzip or StuffIt, you can click the "Add to Zip" or "Add to Sit" option and have these programs automatically archive the file(s) into one. These limitations are often small and don't interfere with the way its full version operations. They're really just implemented as a way to prompt payment. Remember that shareware is not freeware. You shouldn't try to use shareware as commercial software without paying for it. About the only thing that's similar between shareware and commercial software is the way in which they may be bought. Through Dialing Properties, users can determine how a phone and modem dials into an Internet service provider. From just these basic configuration options, you can create your own experience with a computer each time you sit down in front of one. Customizing your PC is what makes using a computer truly unique and enjoyable, so have fun and build a situation at home or a work in which you'll love to work with everyday. Keep your computer's fan clean by preventing the fan from getting dirty or dusty in the first place. Use the computer in a dust-free environment and never smoke around it. 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. If the program were working with a simple algebra equation like, "x + 5 = y," the variables "x" and "y" would be unknown pieces of data. Or if a program were to calculate a date "x" days from now, the variable "x" would be an unknown piece of data until we tell the program what "x" is.