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. Start comparison shopping and look for the "fastest and biggest." By "fastest and biggest," we mean the computer with the fastest processor, the fastest modem, the biggest memory, and the biggest hard drive capacity. Even if you think that you'll never need the amount of speed or space available on the market today, it's important to have in the event that you truly do need that much in the future. But our job is unnecessarily made harder when people don't take the time to learn about computer accessories and familiarize themselves with the limitations of store-bought computers. Hopefully by the time you finish reading this article, you'll understand the lesson that we were trying to teach our client: "What comes out of the box is really just a starter kit. The two most popular software programs used to compress and decompress files are Winzip and StuffIt respectively. There are other programs that do the same thing and there are even programs that can compress and decompress files for both the Windows and the Mac system. However since Winzip and StuffIt are the most popular, we will assume you will use either one to compress and decompress your own files. When executed, they would process each command without the user having to type each and every one of them. When Windows was developed, the need for typing commands was essentially eradicated thanks to the introduction of the point-and-click (mouse) interface. But this didn't stop the batch file fever that started under MS-DOS - and in some small circles, batch files are still as popular as they were in the beginning. For the life of us, we can't figure out why anyone other than a rocket scientist would want to install a different version than this free one that comes pre-installed. Windows calculator has two interfaces: an easy one, and a scientific one. So perhaps a rocket scientist could fare well with Windows Calculator after all!