Depending on how you elected to install Winzip or StuffIt, you may be able to right-click a .zip or .sit file and have the program extract its contents into a new folder for you. Compressing Files When you want to upload a file or email a collection of files to a friend, it's best to archive it as a . As you can imagine, the cumbersome process of switching from floppy to floppy prompted the birth of the operating system. An operating system is a software program that controls how the computer's hardware (and installed software) works. It manages the activity of every component and then displays that activity as a user-friendly interface (GUI). Instead of speaking to a human being, chances are that you spoke to a computer that not only responded to what you said and followed the commands that you gave it, it also asked you for more information such as your full name or credit card number. In this case, a person (such as yourself) operated a computer without even knowing it! gif - This extension indicates another image file and it stands for "Graphics Interchange Format." .Gif files are often smaller than .bmp files (described earlier) and they're commonly found on Internet web pages. .jpg - This extension indicates yet another image file and it stands for "Joint Photographers Experts Group. There are alternatives to selling a computer and this article is going to introduce a few of them. 1. Give it to the kids. This is of course, assuming the kids are too young to whine about not having enough SDRAM or less than a 160GB hard drive. Today's "older" computers are perfectly capable of accommodating the needs of young PC users, and they're excellent machines for playing educational CDs, small multimedia files, or games downloaded from the Internet. Problems in this part of an interface are uncommon, however if you find yourself repeatedly clicking an icon with no results, you can correctly describe the problem by referring to the toolbar. Minimize, Restore, and Exit buttons - these three buttons are usually located on the right-most upper part of a program's interface and each allow you to minimize a program's screen, restore it to its original size, or shut down the program completely.