This indicates that the "Win32_PerfRawData_PerfProc_Process" class does not exist in WMI. This is usually caused by performance counters being disabled. In this case, it is turned off for gathering performance data for processes. This can be confirmed by using the Registry Editor to locate the key "Disable Performance Counters" located in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\PerfProc\Performance.
This setting may not be there at all. That is not a problem. However, if it is there it must be set to 0. Update this value to be 0 and then reboot (probably needed but not sure).
Here's a PowerShell script that does this. Be sure to back up your registry before making any changes.
$value =(Get-Itemproperty hklm:SYSTEM\CurrentControlSet\services\PerfProc\Performance)."Disable Performance Counters"
If ($value -ne 0)
{
Set-ItemProperty -Path hklm:SYSTEM\CurrentControlSet\services\PerfProc\Performance -Name "Disable Performance Counters" -Value 0
}