It's when these accessories are work requirements or when they're needed to produce works of quality for any other reason that they can become rather expensive. And this expense applies to microphones, digital cameras, PDAs, scanners, video cams, and more. Regardless of cost, it's important to understand that accessories can become "necessities," and that the best time to get them is the moment you buy a new computer. 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. 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. For the novice, it's best to buy a computer that has all of these components included so that when it's taken home, assembling the computer is a simple matter of plugging things in where they belong. Save the individual purchases of these components for those who have more experience. 2. Decide what you'll use the computer for. 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. 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. In programming, it's sometimes required to work with unknown pieces of data. That's when conditions come in handy. 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. What we're saying is that since we can try shareware before paying for it, we can determine if the software is completely compatible with our systems first. In other words, we can discover whether the software performs the way we want them to and should anyone try to do the same with commercial software, they'll be in for a big disappointment.