Those errors are the result of Program B attempting to use an outdated (shared) file that was installed by Program A. In order to fix that problem, the user would have to download an updated version of the shared file (which to say the least - is not an easy thing to find or do). Sometimes, errors occur because a system doesn't have the required drivers or the drivers that are on the system are the incorrect version. Today, we have quite a few operating systems. Some of the more popular ones are Windows Vista, Mac OS X, ZETA, IBM, Unix, and Linux. But even still, operating systems have extended onto to non-computer devices such as game consoles, portable music players, and PDAs. Regardless of the device, the operating system installed onto it serves the same purpose across the board: to enable user-to-hardware communication. Commands are the instructions that a computer follows to perform an action. 2 To make them work inside of a program, programmers assign commands to objects like buttons for example. The commands in a program are pretty useless unless they have some data to act on so programmers either give the programs some data to work with (list of names or numbers for example) or they make the program generate it's own data. It's hard for some folks to believe, but the computers of this generation almost run themselves! 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! Although the prices of computers are decreasing, they can still create a hefty expense especially if you need additional peripherals described above. 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. And it's these orphan files that can really clutter up a hard drive and shorten the life of an otherwise, young and robust PC. Orphans are usually files that contain temporary data created by a program, files created by the user, partial files left over from a computer crash, or any other kind of miscellaneous files created for almost any other reason.