A powered computer lacking an operating system wouldn't display anything more than a bunch of confusing text messages that describe the computer's boot process. At the very end of this process, the computer looks for an operating system and if not found, it will prompt the user to tell it where it is. 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). 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. 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. NOTE: Some of these tools include kid-specific web browsers that will visit pre-approved websites. Others include browser plug-ins that won't allow access to online areas that contain forbidden keywords. Most main menus display themselves as soon as a device is turned on, so chances are that if you're standing before a device that shows a bunch of choices to do something, you're looking at a main menu. The buttons on these main menus of course take you to additional menus, which in turn give you even more choices to make. Selling Your Computer Looking At Alternatives At some point, your needs are going to outgrow the capabilities of your computer. You may find yourself in need of more hard drive space for all those videos and mp3s that you download, for example. Or maybe that cool new programming language you've been dying to try requires more memory than what your computer currently has.