...
MD5 md5Checksum = MD5.Create();
using (FileStream fs = File.Open(filename, FileMode.Open))
{
computedHash = FormatHashChecksum(md5Checksum.ComputeHash(fs));
}//using
...
private static string FormatHashChecksum(byte[] hashArray)
{
return BitConverter.ToString(hashArray).Replace("-", "").ToLower();
}//FormatHashChecksum