Failing Classic ASP in reason of certificate (MSXML2.ServerXMLHTTP.6.0 e WinHTTP.WinHTTPRequest.5.1)

My Classic ASP code failing:

if run this way:
SET obj_http = Server.CreateObject("MSXML2.ServerXMLHTTP.6.0")

obj_http.open "POST", urlws, False
obj_http.setRequestHeader "Content-Type", "text/xml; charset=utf-8"
obj_http.setRequestHeader "SOAPAction", "urn:XXXXXXXXX"
obj_http.setRequestHeader "Authorization", "Basic " & Base64Encode( rTrim( sUsuarioTransmissao ) & ":" & rtrim( sSenhaTransmissao ) )

' Configurar certificado cliente
' Formato: StoreLocation\StoreName\Thumbprint
obj_http.setClientCertificate "LOCAL_MACHINE\MY\" & sThumbprint

obj_http.send sXML

error is "Object doesn't support this property or method: 'setClientCertificate'"


if run this way:
SET obj_http = Server.CreateObject("WinHTTP.WinHTTPRequest.5.1")

obj_http.open "POST", urlws, False
obj_http.setRequestHeader "Content-Type", "text/xml; charset=utf-8"
obj_http.setRequestHeader "SOAPAction", "urn:XXXXXXXXX"
obj_http.setRequestHeader "Authorization", "Basic " & Base64Encode( rTrim( sUsuarioTransmissao ) & ":" & rtrim( sSenhaTransmissao ) )

' Configurar certificado cliente
' Formato: StoreLocation\StoreName\Thumbprint
obj_http.setClientCertificate "LOCAL_MACHINE\MY\" & sThumbprint

obj_http.send sXML

error is "A certificate is required to complete client authentication"