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 .zip or .sit extension). Double-clicking one of these kinds of files will open up a window that displays the contents of the archive. But perhaps most importantly for the end-user, the operating system is responsible for translating commands issued with a keyboard and mouse into binary code (010110101 stuff) that can communicate with a set of speakers, a printer, a scanner, and more. With an operating system installed onto a computer's hard drive, users no longer need to boot a computer with a floppy disk, nor do they need to run programs from a floppy disk. Remember that computers essentially run off of a series of commands and it's usually a smooth process. But when one command conflicts with another command - or when one command asks for a process or information that isn't available, the computer returns results that aren't useable. That's an error. A prime example of this kind of error is when users attempt to use software that isn't applicable for their system. You could end up typing a command as wide as your computer screen or worse, long enough that the entire command would have to wrap onto the next line! Now imagine having to type these long commands every time that you wanted to start a program. Yikes! That's one of the reasons why batch files became so popular. The above illustrations were just a couple of examples of how far computer technology has grown, and how far we've pushed "user-friendliness" to its limit. Eventually, the keyboard and mouse will have to play a role when computer newbies have to work with one as a cash register, as a hotel booking program, or as a library's catalog system. As previously mentioned, preventing dust from entering the computer is extremely important and will reduce the need to open and dust your system in the first place. The severity of outside elements (smoking, humidity, pets, etc.) will ultimately determine how often you'll need to de-dust your machine.