The only advice I'd give on buying a PC is pretty basic. Two key things: 1: You can save a lot of money by staying back from the leading edge of CPU speed, but CPUs are rarely a drop-in upgrade. 2: Have expansion in mind. With USB you don't need to worry quite so much about space inside the case, but RAM slots are a limit. If you have four memory slots, don't get 1GB of RAM as 4 x 256MB. When I made mistake #2, the SIMMs were measured in kilobytes.