An operating system is a software program that controls how the computer's hardware (and installed software) works. It manages the activity of every component and then displays that activity as a user-friendly interface (GUI). It keeps track of where things exist on a computer's hard drive as well. But perhaps most importantly for the end-user, the operating system is responsible for translating commands issued with a keyboard and mouse into binary code (010110101 stuff) that can communicate with a set of speakers, a printer, a scanner, and more. This section is reserved for solving problems specific to the software or hardware that you're using. 2. Product websites. If you're having a problem with a piece of software or with a hardware part, try the website of that software's or hardware's manufacturer. Most (if not all) manufacturer's reserve a portion of cyberspace and dedicate it to support the products that they build. Many different programs often share Dynamic Link Libraries and you'll find a bunch of them in the Windows/System directory (but don't ever delete them)! .exe - This extension indicates a program or an application like Microsoft Word, Internet Explorer, or Outlook Express. Use extreme caution when downloading . 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. Even ordering a pizza is now a simple matter of dialing from a wireless cell phone and making a few selections from series of pre-programmed menus! But you can prevent identity theft from occurring by installing a firewall. A firewall is software that checks all data entering and exiting a computer and it then blocks that which doesn't meet specified security criteria (user-defined rules).1 5. Don't click on website links in spam messages. In an effort to obtain personal information, some spammers will send email that asks you to click on a link. It hasn't gone anywhere, but its competition with commercial software is fierce - so fierce that it tends to fall on the back burner among new computer users. This is unfortunate because shareware has so many advantages over commercial software. One of those advantages is its cost. On the whole, shareware is generally cheaper than commercial software.