You must have a Prescott P4.
If so, 47 is not bad believe it or not. Many people would even consider it "normal". Usually Prescotts operate at 70C at load. Make sure the air flow in your PC is adequate. You might consider buying some case fans. Put one under your HD sucking cold air in and one at the back sucking hot air out. You might have to drill some holes if you don't have any. Right now it seems you only have a CPU fan. Or consider replacing your current CPU cooling solution. Try Artic Cooling or Artic Silver. Your ambient temp is fine but it could be better.