C# - Umgebungsvariablen abrufen

private string getEnv()
    {
      StringBuilder SB = new StringBuilder();
      IDictionary Dic =  Environment.GetEnvironmentVariables();
      foreach (DictionaryEntry de in Dic)
      {
        SB.Append(de.Key);
        SB.Append(": ");
        SB.Append(de.Value);
        SB.Append(Environment.NewLine);         
      }
      return SB.ToString();
    }