def find_steam_location():
  """
  Finds the location of the current Steam installation on Windows machines.
  Returns None for any non-Windows machines, or for Windows machines where
  Steam is not installed.
  """
  if registry is None:
    return None

  key = registry.CreateKey(registry.HKEY_CURRENT_USER,"Software\Valve\Steam")
  return registry.QueryValueEx(key,"SteamPath")[0]
Finds the location of the current Steam installation on Windows machines.
  Returns None for any non-Windows machines, or for Windows machines where
  Steam is not installed.