Example of a hex to string conversion and string to hex.

hex2string.cs

//DECODE -> HEX TO STRING
String wHexString = "THIS IS A CONVERSION TEST";
byte[] wRaw = new byte[wHexString.Length / 2];
for (int i = 0; i < wRaw.Length; i++)
{
  wRaw[i] = Convert.ToByte(wHexString.Substring(i * 2, 2), 16);
}
String iStack = Encoding.ASCII.GetString(wRaw);

//ENCODE -> STRING TO HEX
Char[] wStack = iStack.ToCharArray();
foreach (Char wLetter in wStack)
{
  int wNumber = Convert.ToInt32(wLetter);
  wStackString += String.Format("{0:x2}", (uint)System.Convert.ToUInt32(wNumber.ToString()));
}