Re:1. run task manager (Score 1)

According to Microsoft System Idle Process does obscure hardware related utilization - for instance without an offloading NIC one bit of network traffic utilizes 1 Mhz of CPU - may not seem like a lot, but if you max out your 1Gb NIC and your system seems slow you may know why (not to mention the disk thrashing and system overhead on an IDE or SATA system - as opposed to a SCSI system where the controller has processing on the controller.