Buying a personal computer can be as difficult as buying a car. No matter how much one investigates, how many dealers a person visits, and how much bargaining a person has done on the price, he still may not be really certain that he has gotten a good deal. There are good reasons for this uncertainty. Computers change at much faster rate than any other kind of product. A two-year-old car will always get a person where he wants to go, but a two-year-old computer may be completely inadequate for his needs. Also, the average person is not techn ....