Há muitas postagens sobre essa mensagem de erro exata. Aqui estão alguns trechos que devem ajudar! #LMGTFY:)
De um KB da Symantec: link
This error happens even if the account is a Local Administrator and the command line is run with administrator privileges.
To solve the problem, UAC filtering for local accounts must be disabled by creating the following DWORD registry entry and setting its value to 1:
[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System] LocalAccountTokenFilterPolicy
De um fórum da Microsoft: link
Because of User Account Control (UAC), the remote account must be a domain account and a member of the remote computer Administrators group. If the account is a local computer member of the Administrators group, then UAC does not allow access to the WinRM service. To access a remote WinRM service in a workgroup, UAC filtering for local accounts must be disabled by creating the following DWORD registry entry and setting its value to 1:
[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System] LocalAccountTokenFilterPolicy
Temos outra pergunta não respondida sobre isso. Talvez eles possam ser mesclados: Habilitando o Powershell Remoting, o acesso é negado?