Computers are not much good at teaching - they are much better used as mind tools to extend the mind's ability in terms of memory capacity and visualisation. The provisionality of tools within the standard desktop or laptop are also ripe for use as a means to express creativity. If used well, computers have a deep impact on human elarning. If used badly though, all a computer can do for us is to perpetuate our errors.
"My computer may be able to beat me at chess, but it's no match for me at kickboxing..."