Imports System.Security.Cryptography
Imports System.IOImports System.Text

'Next, we will get the raw MD5 hash of our file. Please note that I will be using the file "C:\MyPic.jpg". 
'You will need to change that to whatever file you'll be getting the hash of.

Dim md5 As MD5CryptoServiceProvider = New MD5CryptoServiceProvider
Dim f As FileStream = New FileStream(TextBox1.Text, FileMode.Open, FileAccess.Read, FileShare.Read,  8192 )

f = New FileStream(TextBox1.Text, FileMode.Open, FileAccess.Read, FileShare.Read,  8192 )md5.ComputeHash(f)
f.Close()          

Dim hash As Byte() = md5.Hash                
Dim buff As StringBuilder = New StringBuilder                
Dim hashByte As Byte                

For Each hashByte In hash                        
       buff.Append(String.Format("{0:X2}", hashByte))                
Next

Dim s as String = buff.ToString() 'final MD5 Checksum

Imports System.Security.Cryptography
Imports System.IO
Imports System.Text

f = New FileStream(TextBox1.Text, FileMode.Open, FileAccess.Read, FileShare.Read,  8192 )
md5.ComputeHash(f)
f.Close()          

'this utility class aides in converting string to bye array which is what out has implementation needs

Dim inputPassword as String = "mypass"
Dim encode as new System.Text.UnicodeEncoding
Dim inputPasswordBytes() as byte = encode.GetBytes(inputPassword)

Dim hash() as byte
' get hash
dim md5 as new System.Security.Cryptography.MD5CryptoServiceProvider
hash = md5.ComputeHash(inputPasswordBytes)

' convert hash value to hex string
dim sb as new System.Text.StringBuilder
dim outputByte as byte
for each outputByte in hash
' convert each byte to a Hexadecimal upper case string
sb.Append(outputByte.ToString("x2").ToUpper)
next outputByte

Debug.Print("The hash is = " & sb.ToString())