On my Windows 10 version 1903, I get:

C:\> typeperf "\System\Processor Queue Length" -si 1
Fin du programme, veuillez patienter...
Erreur : aucun compteur valide.

C:\> echo %errorlevel%
-268435454

Error message in english: "Error: No valid counters"

Because of this error, regrtest fails with:

...
  File "C:\vstinner\python\master\lib\test\libregrtest\win_utils.py", line 85, in getloadavg
    typeperf_output = self.read_output()
  File "C:\vstinner\python\master\lib\test\libregrtest\win_utils.py", line 82, in read_output
    return overlapped.getbuffer().decode()
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xff in position 74: invalid start byte


I'm using:

platform.architecture: 64bit WindowsPE
platform.platform: Windows-10-10.0.18362-SP0
sys.windowsversion: sys.getwindowsversion(major=10, minor=0, build=18362, platform=2, service_pack='')

Note: same error when testing as an administrator. It's not a permission issue.

--

On the other side, "wmic cpu get loadpercentage" works as expected:

C:\> wmic cpu get loadpercentage
LoadPercentage
1
1