In Windows NT 4.0, disk counters were off by default, and had to be enabled type typing diskperf -y.

In Windows 2000, physical disk counters are enabled by default, but logical disk objects are disabled, until you type diskperf -yv

The syntax of the diskperf command is:

diskperf \[-Y\[D|V\] | -N\[D|V\]\] \[\\computername\]

Where:

      <b>-Y</b>  Sets the system to start all disk performance counters.
      <b>-YD</b> Enables the disk performance counters for physical drives.
      <b>-YV</b> Enables the disk performance counters for logical drives or storage volumes.
      <b>-N</b>  Sets the system to disable all disk performance counters.
      <b>-ND</b> Disables the disk performance counters for physical drives.
      <b>-NV</b> Disables the disk performance counters for logical drives.
      <b>\\computername</b> Is the name of a remote computer.
NOTE: All enabling actions require a restart.