For fun, let's investigate just how little knowledge these thousand-dollar machines actually require. Can an absolute newbie operate a computer without knowing how to use a mouse or keyboard? Assuming that a computer is set up to operate on voice command - sure! Voice command software allows users to tell a computer what to do and the computer responds by fulfilling the user's commands. The following list defines some of the most common extensions that you'll find on your computer. .au - This extension indicates a sound file. Most sound players will load up and play this kind of file. .art - This extension indicates an image file that was compressed with AOL (America Online) technology. Title bar - this is the top-most part of a program that displays its own name or it may describe the contents displayed in another part of the interface. If a program is incorrectly coded, you may see a wrong description in this part of its interface. Menu bar - this part of a program displays menu items and menu options. In addition, you'll need to figure in costs for maintenance, servicing, and insuring. 4. Start comparison shopping and look for the "fastest and biggest." By "fastest and biggest," we mean the computer with the fastest processor, the fastest modem, the biggest memory, and the biggest hard drive capacity. Accessibility Options. Speaking of visual problems, another setting that's useful is accessibility options. This setting allows people with disabilities to use a computer that accommodates vision and hearing problems. Keyboard and Mouse Options. The keyboard and mouse controls give users the option of speeding up or slowing down the movements of both of these peripherals. A simple Google or Yahoo search for a particular type of program will yield all sorts of results that point you toward items that you can try before you buy. Be aware however, that because shareware is not commercial software, you may not experience a full program the way you would if you bought the software out of a box.