You'll need a can of compressed air and an anti-static rag to remove stubborn clumps of dust. Hold the can perfectly vertical and spray the fan being careful not to spray the dust off the fan onto other sensitive parts of the computer like circuit boards or inside the motor casing. Wipe up remaining dust with your anti-static rag and then reassemble the computer. The truth of the matter is that the programs pre-installed are great tools for the beginning computer user. At some point down the road, usage will dictate a need for more powerful applications. We may need a word processor that can convert a document into an HTML page or PDF document. We may need a calculator that solves geometric problems. Fortunately you have this article to guide you through some of the most common extensions that you'll run into. But before you can see file extensions, you need to turn them on. From Windows Explorer, click on the "Tools" menu, and select "File Options." Click the "View" tab and then uncheck the box next to "Hide file extensions for known file types. You and your children may not always agree about what's appropriate, but as a guardian, you're in control and you're ultimately responsible for their safety. Take the time to investigate software tools that put you in control and allow you to block access to certain websites. If you use an online service like AOL (America Online), you can use its internal Parental Control settings to block access to various chatrooms and websites. 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! The important thing to realize here is that this phenomenon isn't a new convenience - it's a new requirement. Enabled by a username and password, individual desktop settings (icons, background picture, and other settings) are available after logging onto Windows. Display Properties. Through Display Properties, a user can change the background of the Windows Desktop, add a screensaver, change the overall color scheme and fonts of Windows, and adjust a computer's color depth and/or resolution (screen area).