Why do the counters in the Exchange counters page always show "NA"?
Reason: This problem occurs when the WMI classes are not registered in the remote machine where Exchange server is running.
Solution: Execute the following commands in the command prompt of remote machine and wait for one poll interval and check whether the data is shown properly for the Exchange server monitor.
The commands differ with the operating system:
* For Windows 2000 the command is 'winmgmt /resyncperf'
* For Windows XP and 2003 the command is 'wmiadap /f'