Unless the activities on your computer are restricted to pure textual output (plain text files), your computer is going to get filled with a lot of "stuff" - stuff that can overfill a PC's capacity too much for the computer to function well. The problem is that while upgrading a computer is always an option, technology advances so fast that newer products (such as memory chips, new drives, etc. It keeps track of where things exist on a computer's hard drive as well. 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. Known as "kiosks," these programs are already in use world wide at ATM machines, employment centers, and in health monitoring systems. Neither a mouse nor a keyboard is required. A computer user only needs to touch various boxes on a screen to control a computer. Sure, the programming behind such technology is extensive and advanced, but to the end user, it makes computer use less intimidating and plain easy. Check box - a check box is a small box that allows a user to indicate several choices among many. When clicked, a small "x" displays inside a box. Similar to the check box, a radio button allows a user to indicate a single choice among many. Problems with radio buttons and check boxes occur when a user makes one choice, but the interface reacts as if the user made many choices (or none at all). Some viruses are a combination of each, however they can be further identified according to where they're located on a computer. A virus originating from the boot sector of a computer is a boot-sector virus and this nasty devil does its dirty work the moment a computer is turned on. A virus that attaches itself to (infects) other programs is a file virus and activates the moment that an infected program starts. 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. One of the easiest and least expensive things you can do to extend the life of your computer is to get rid of unnecessary programs, folders, and files.