I have a 1.7 GHz Dimension 8100 w/Win2k and OfficeXP. We run extensive Excel models that iterate using Solver. I have noticed that after a period of non-user interaction, the model slows noticeably. If I move the mouse and click on something else (e.g., the Start button), the model speeds back up. It acts like the processor slows for some power-saving feature or something. Does anyone know if the processor can slow on this machine (like a laptop)?