Parts Are Always Changing After only 15 years or so, the PC is in its sixth CPU generation (with such devices as the AMD K and Intel Pentium II. As a result, anew generation matures every 24 to 36 months (although the newer generations have been arriving into months. Even the standardized products, such as CD-ROM drives, have proliferated indifferent speeds and versions (8, 10´, 12´, 16´, and even 20´ speeds. Once production stops fora drive or board, stock rarely remains for very long. You see, even if you know what the problem is, the chances of your locating an exact replacement part are often quite slim if the part is more than two years old. Notice the word exact—this is the keyword in PC repair.