static void Main()

    byte[] data = FromHex("47-61-74-65-77-61-79-53-65-72-76-65-72");

    string s = Encoding.ASCII.GetString(data);

public static byte[] FromHex(string hex)

    hex = hex.Replace("-", "");

    byte[] raw = new byte[hex.Length / 2];

    for (int i = 0; i < raw.Length; i++)

    {

        raw[i] = Convert.ToByte(hex.Substring(i * 2, 2), 16);

    }

    return raw;