Gas stations are self-serviced through a menu-clad touch screen kiosk. Most cash registers are Windows XP or Vista machines that send purchase details back to headquarters via the Internet (or a small Intranet). Having your weight, blood pressure, and heart rate measured and recorded is now a digitized process. Those who've purchased and used a computer in the past already have an idea of what they need in a new computer. But those who are new to the computer world could get lost in the myriad of choices available. The short answer to "What should I buy?" is "The best." Of course that answer is extremely subjective because "the best" to one person is certainly different to another. What we're saying is that since we can try shareware before paying for it, we can determine if the software is completely compatible with our systems first. In other words, we can discover whether the software performs the way we want them to and should anyone try to do the same with commercial software, they'll be in for a big disappointment. 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 to make a delicious batch of chocolate chip cookies, we would need to "accessorize" this dough with chocolate chips and a little brown sugar. 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. 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.