So much emphasis is put on maintaining a computer's operating system that we sometimes forget how important it is to maintain a computer's hardware components. Since there can be quite a few components to take care of, let's talk about the most important one. The most important component of a computer's hardware system is its fan. Sure, one could upgrade the operating system to accommodate the demands of a new piece of hardware, but trouble starts when that new operating system requires new hardware in return. If we're not careful, we could end up replacing almost every hard and soft part of a computer that we own - all in an effort to upgrade! Kids will enjoy the ability to play multi-player games and adults will enjoy the ability to blast a single message to everyone at once or maintain a group schedule. Since we're describing a home network that will connect to the Internet, you're strongly advised to install a protective firewall program to thwart Internet viruses, worms, or other damaging spyware code. Open Source Software If you've spent any lengthy amount of time on the Internet, you've probably heard of open source software but might not have fully understood what it is and why it even exists. This article will describe this recent phenomenon and describe some of its benefits for the software using community. Conditions allow a program to perform an action based on the outcome of a previous command.3 Using this type of instruction, we could instruct a program to do one thing if the "x" variable in our latter example turned out to be 7 days, and then do different thing if the variable turned out to be 3 days. Apparently, the Windows XP operating system requires components that weren't developed at the time Windows 98 was distributed and if we were to install Windows XP on this machine anyway, the new operating system would look for hardware that the computer didn't have. And that would be an instant recipe for failure.