Some viruses are a combination of each, however they can be further identified according to where they're located on a computer. A virus originating from the boot sector of a computer is a boot-sector virus and this nasty devil does its dirty work the moment a computer is turned on. A virus that attaches itself to (infects) other programs is a file virus and activates the moment that an infected program starts. Although Window's defrag system can ease some of the stress that these files place onto the drive, it doesn't do much to get rid of the problem in the first place. This is because the defrag program simply organizes the files in a system that makes it easier for the computer to access. (Thus cutting down on the work required to find and load them). 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! Other tools available online operate similar to the way that AOL's Parental Control settings work, however no collection of tools could replace the reinforcement of mom and dad. Never let your children speak with strangers and never leave them alone at the computer unattended. Children just don't have the experience that adults have and they don't have the skills required to handle inappropriate conversations, emails, or images found online. One of the biggest problems that new computer users have with technical support is not knowing how to correctly describe the problem that they're having. And it isn't fair to expect a tech support person to automatically know what a "thing-a-ma-jingy," or "whatcha-ma-call-it" is. The following describes the correct names for common components of software so that when you experience a problem, you can effectively describe an issue that you're having and a technician can readily resolve it. ) 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. Then let's say that the user of that computer downloads and installs Program B.