I am using this as a seperate class: Public Class HexConverter
    Private Property _HexString As String
    Private Property _HexBytes As Byte()
    Public Property HexString As String
        Get
            Return _HexString
        End Get
        Set(ByVal value As String)
            _HexString = value
            _HexBytes = HexToBytes(value)
        End Set
    End Property
    Public Property HexBytes As Byte()
        Get
            Return _HexBytes
        End Get
        Set(ByVal value As Byte())
            _HexBytes = HexBytes
            _HexString = BytesToHexString(value)
        End Set
    End Property
    Private Function HexToBytes(ByVal Hex As String) As Byte()
        Dim Result As New List(Of Byte)
        If Not HexIsValid(FormatHex(Hex)) Then Throw New Exception("Invalid hexidecimal number cannot be converted!")
        For I = 0 To FormatHex(Hex).Length - 1 Step 2
            Result.Add(Convert.ToByte(FormatHex(Hex).Substring(I, 2), 16))
        Next : Return Result.ToArray()
    End Function
    Private Function BytesToHexString(ByVal Bytes() As Byte) As String
        Return "&H" & Replace(BitConverter.ToString(Bytes, 0), "-", "&H")
    End Function
    Private Function HexIsValid(ByVal Hex As String) As Boolean
        For Each Nibble As String In Hex
            If "0123456789ABCDEFabcdef".IndexOf(Nibble, 0) = -1 Then Return False
        Next : Return True
    End Function
    Private Function FormatHex(ByVal Hex As String) As String
        Hex = Replace(Hex, "&h", "") : Hex = Replace(Hex, "&H", "")
        If (Len(Hex) Mod 2) = 1 Then Hex = "0" & Hex
        Return Hex
    End Function
    Public Shadows Function ToString() As String
        Return _HexString
    End Function
End Class

This is how Im calling it (Button Click)
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        'Your Hex String
        Dim SampleHexString As String = newkey.Text
        'Create a new Hex Converter
        Dim HexConverter1 As New HexConverter
        'Change the value of the Hexconverter by setting the string
        HexConverter1.HexString = SampleHexString
        'Get the conversion result from the hexconverter
        Dim ResultBytes As Byte() = HexConverter1.HexBytes
        'Create a new hexconverter to test that it works
        Dim HexConverter2 As New HexConverter
        'This time change the value of the hex converter by setting its bytes instead of
        'setting its string
        HexConverter2.HexBytes = HexConverter1.HexBytes
        'check if the conversion matches the original string
        If SampleHexString = HexConverter2.ToString And SampleHexString = HexConverter2.HexString Then
            MsgBox("The class works.")
        Else
            MsgBox("The class does not work")
        End If
    End Sub

When I call it I am trying to take the string from the textbox as seen  in this line:         Dim SampleHexString As String = newkey.Text