Encoding.GetEncoding("ISO-8859-1")
string isocontent = Encoding.GetEncoding("ISO-8859-1").GetString(fileContent, 0, fileContent.Length);
byte[] isobytes = Encoding.GetEncoding("ISO-8859-1").GetBytes(isocontent);
byte[] ubytes = Encoding.Convert(Encoding.GetEncoding("ISO-8859-1"), Encoding.Unicode, isobytes);
return Encoding.Unicode.GetString(ubytes, 0, ubytes.Length);