You may find that when you go to run perfmon, the Windows performance counters are missing. To restore missing performance counters, from the Windows installation media or another Windows machine of the same operating system, copy and replace C:\Windows\System32\perfc009.dat and C:\Windows\System32\perfh009.dat, then restart Windows.
If the performance counters are still missing after doing the above, you might try the following:
- Check the following registry key to see if the performance counter is disabled (where <<servicename>> is the name of the service whose performance counter is missing) HKLM\System\CurrentControlSet\Services\<<servicename>>\Performance (0 means the counter is enabled, 1 means the counter is disabled, 2 means the 32 bit counter is disabled and 3 means the 64 bit counter is disabled)
- To restore all missing performance counters, run the following script in the command prompt:
Missing performance counters is typically caused by a corruption or programs using WMI to modify the registry, so I would be cautious using the computer and troubleshoot for hard drive failure and possibly even rebuilt Windows if it’s an important computer (which it probably is if you are running performance testing on it).