As this thread has reached the status of manual for new computer buyers (and very useful too), I ought to chip in my pennyworth from the point of view of somebody who uses the pc mainly for music activities. If you write music and want the computer to give you a good simulation of what real musicians would make of it, you will sooner than later be in the market for sound library programmes and samplers. These use up CPU power big time. They also require lots of RAM. 1G is the recommended minimum these days in the computer music world, and some programmes won't load on less. So if you settle for 512MB, be sure the pc is expandable. Also, if you are likely to want separately powered speakers to replace the rubbish that comes as standard, or a MIDI controller keyboard, make sure you have enough USB ports to go round. Four is the minimum, and even then, you may run short.