If you download a compressed file from a website or file library that ends in an .exe extension, take note that although the file is compressed, it's typically a file that will install a program onto a computer. .Zip or .Sit files don't install software - they merely archive a collection of them into one, or they significantly reduce the size of a larger one. Earlier computers didn't have an operating system and if you have experience with the computers of the early eighties, you'll remember that most to them didn't even have a hard drive! These old computers booted an MS-DOS type operating system from drivers stored onto a floppy disk, and in order to use a program, users would remove the boot floppy and then insert a new floppy that contained the program. The worst thing anyone could do is snoop around crucial Window directories and haphazardly delete files that don't look familiar. Doing so could render important programs inoperable, corrupt the Windows operating system, and possibly prevent the computer from even starting. That's why using special deletion software is so important. Since the computer in use may be shared with others, Passwords gives the almighty administrator the means to determine whether all users will share the same preferences and desktop settings or if users can customize preferences and desktop settings. Regional Settings. Things get really personal in Regional Settings - as this configuration makes changes according to a user's location and language. The network card is similar to the old modems we used in the past to connect to the Internet, however in a home network, it's used to communicate with every computer that's connected to it. You'll want to first, select the computers that will connect to each other and then install the network cards inside each of them. That dot and group of three letters is known as an "extension," and the extension explains what kind of file it is. A file could be a plain text file, an image, a sound, a video, or program. But without seeing the extension, you wouldn't know it unless you double-clicked on it. The following list defines some of the most common extensions that you'll find on your computer.