Windows service на Python: access denied

class AppServerSvc (win32serviceutil.ServiceFramework):
_svc_name_ = "TestService"
_svc_display_name_ = "Test Service"
 
def __init__(self,args):
    win32serviceutil.ServiceFramework.__init__(self,args)
    self.hWaitStop = win32event.CreateEvent(None,0,0,None)
 
def SvcStop(self):
    self.ReportServiceStatus(win32service.SERVICE_STOP_PENDING)
    win32event.SetEvent(self.hWaitStop)
 
def SvcDoRun(self):
    servicemanager.LogMsg(servicemanager.EVENTLOG_INFORMATION_TYPE,
                          servicemanager.PYS_SERVICE_STARTED,
                          (self._svc_name_,''))
    self.main()
 
def get_next_msg(self):
    address = ('localhost', 6000)
    listener = Listener(address, authkey='secret password')
    conn = listener.accept()
    msg = conn.recv()
    listener.close()
    return msg
 
def process_msg(self):
    token = win32security.OpenProcessToken(win32process.GetCurrentProcess(), 
                 win32security.TOKEN_ALL_ACCESS)
 
    duplicated = win32security.DuplicateToken(token, 2)
 
    curr_proc_id = win32process.GetCurrentProcessId()
    curr_session_id = win32ts.ProcessIdToSessionId(curr_proc_id)
 
    # access denied! error code: 5
    win32security.SetTokenInformation(duplicated, win32security.TokenSessionId, curr_session_id)
 
def main(self):
    while True:
        msg = self.get_next_msg()
        self.process_msg()
 
 
if __name__ == '__main__':
    win32serviceutil.HandleCommandLine(AppServerSvc)