Other times, the data is unknown. If the program were working with a simple algebra equation like, "x + 5 = y," the variables "x" and "y" would be unknown pieces of data. 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. Today's "older" computers are perfectly capable of accommodating the needs of young PC users, and they're excellent machines for playing educational CDs, small multimedia files, or games downloaded from the Internet. And don't forget the most important role they play in a child's homework-clad life: A simple encyclopedia CD on a used computer makes excellent research tool (not to mention a rather fancy calculator! The good news is that there are some practical steps you can take to protect your children from sexual predators, hackers, and other seedy individuals who want to cause harm. This article will describe a few of them. The first step in protecting your children at the computer is to prevent their access to passwords. This is almost unheard of in stores like Best Buy, Circuit City, or Egghead, yet the shareware programs offered within this price range rival even Microsoft's Office suite. Another advantage that shareware has over commercial software is its compatibility. We're not saying that shareware is compatible with all operating systems. In these situations, problems occur the moment that a piece of software attempts to access the things (hardware, memory, space, resolution, etc.) that it cannot find. Because some programs share common files, errors can also occur when these shared files are not up to date. For instance, let's say that Program A is already installed on a computer and it's working just fine. If we want to use this dough into in a warm loaf of sesame seed bread on the other hand, we'd need to "accessorize" the dough with yeast and sesame seeds. Like "plain dough," the brand new computer isn't very useful by itself. It needs accessorizing. Depending on what's needed, accessorizing doesn't need to be expensive.