code: def get_explorer_pid(self):
          
          try:
              exp = win32.SHGetFolderPath(win32.CSIDL_WINDOWS)
          except Exception:
              exp = None
          if not exp:
              exp = os.getenv('SystemRoot')
          if exp:
              exp = os.path.join(exp, 'explorer.exe')
              exp_list = self.find_processes_by_filename(exp)
              if exp_list:
                  return exp_list[0][0].get_pid()
          return None
docs: Tries to find the process ID for "explorer.exe".
  
          @rtype:  int or None
          @return: Returns the process ID, or C{None} on error.