I have a new Dim 4100 933. My CPU usage starts at almost 0 just after reboot but climbs to & stays at almost 80% after just moving mouse & opening a few programs even after closing all programs. I have TclockEx to monitor CPU usage but have same results with System Monitor & Wintune results. I've disabled everything I can with msconfig & closed all running programs with End Task with same results. System seems to work OK but this much background CPU usage can't help performance. Any ideas would be appreciated.