You probably need to activate the disk counters by typing 'diskperf -y' at the command prompt. The counters will start after the next reboot. If you have the correct permissions you can run diskperf from a remote machine by typing 'diskperf -y \\machinename'

Will diskperf -y increase the load on my machine? This is best answered by quoting from two well known technical sources :-

"By default, the drivers necessary to collect information on the disk subsystem are disabled to avoid the overhead for this process. This overhead is negligible, however, and should not affect your results."- (Windows NT Performance Tuning and Optimization, Kenton Gardinier)

"Diskperf installs the Disk Performance Statistics Driver that collects data for Performance Monitor and a high-precision timer that times each transfer. The timer and the driver are omitted by default to avoid their overhead when you are not monitoring disk performance. This overhead has been measured at less than 1% on a 33-MHz 486 processor."- (Microsoft Windows NT Resource Kit, Microsoft Press)