avi - This extension indicates a video file playable by most multimedia viewers including Microsoft's Media Player. .bmp - This extension indicates another image file that might have originated from Windows Paint program. .dll - This extension indicates a Dynamic Link Library which may contain additional programming code for software. Automating Things with Batch Files They Work on Today's Computers Too! If you're familiar with MS-DOS at all, you'll recall that it's a command-driven operating system that performs functions issued at the C:> prompt. The only way to get an MS-DOS computer to do something was to type a command at this prompt and if you can imagine, it was a rather cumbersome way to use a computer. In the business world, open source is all about image and when consumers witness corporations contributing (instead of selling) to the buying public, they gain big favor in the eyes of their users (plus tremendous opportunities to sell other items). Inviting the public inside a product's development builds community and trust. Double-clicking one of these kinds of files will open up a window that displays the contents of the archive. In most cases, you can double click a file inside this window to use it, or you can select it and drag the file to a folder to view later. Depending on how you elected to install Winzip or StuffIt, you may be able to right-click a . 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. Others include browser plug-ins that won't allow access to online areas that contain forbidden keywords. Another step requires teaching your children to never ever volunteer personal information. Under no circumstances, should children give their personal names, home addresses, phone numbers, or school information to anyone over the Internet regardless of the situation.