Your computer's hard drive is an information storage unit. Basically all of the information retained inside your computer is kept on the hard drive. This includes all of the programs that you have installed, settings that you might have set, and any documents or things that you have created and then saved. Most people realize that this sort of information is somehow kept inside their computer, now you know that it is kept on your hard drive.
The computer keeps an index of all of the information kept on your hard drive known as a File Allocation Table. When you put any information on the hard drive you give that information a name and that name is known as a file name. The information itself is stored as electronic pulses on a magnetic disk. If you tell the computer the file name it can look up the location of the file in its File Allocation Table, go to the right spot (or spots) on the hard drive. There it can read the magnetic pulses and convert the set back into information. Maybe some of this is kind of high tech and you don't need to know all the details, but if you wish to have any hope of finding anything on your hard drive (i.e. finding any information in you computer) it is essential that you at least understand that the information is kept in a file, on the hard drive and you need to know the file name where the information is kept in order to find the information. Fortunately you can look at all the files on your computer's hard drive using a program called Windows Explorer.