''' Here are all the factors that are sent from the calling program
    Protected Friend WriteOnly Property KeyLetters() As String
        Set(ByVal Value As String)
            Key_Letters = Value
        End Set
    End Property

    Protected Friend WriteOnly Property KeyNumbers() As String
        Set(ByVal Value As String)
            Key_Numbers = Value
        End Set
    End Property

    Protected Friend WriteOnly Property KeyChars() As Integer
        Set(ByVal Value As Integer)
            Key_Chars = Value
        End Set
    End Property

    Protected Friend WriteOnly Property Type() As String
        Set(ByVal Value As String)
            WType = Value
        End Set
    End Property

    ''' GENERATES A RANDOM STRING OF LETTERS AND NUMBERS.
    ''' LETTERS CAN BE RANDOMLY CAPITAL OR SMALL.
    ''' <returns type="String">
    '''  RETURNS THE RANDOMLY GENERATED KEY

    Function Generate() As String
        ''' CONVERT LettersArray & NumbersArray TO CHARACTR ARRAYS
        If WType = "L" Then
            LettersArray = Key_Letters.ToCharArray
        Else
            NumbersArray = Key_Numbers.ToCharArray
        End If

        For i_key = 1 To Key_Chars
            ''' START THE CLOCK
            Randomize()
            Random1 = Rnd()
            Thread.Sleep(10)
            Randomize()
            Random2 = Rnd()
            arrIndex = -1
            ''' IF THE VALUE IS L GENERATE A LETTER,
            ''' OTHERWISE WE GENERATE A NUMBER 
            If WType = "L" Then
                ''' GENERATE A RANDOM INDEX IN THE LETTERS
                ''' CHARACTER ARRAY
                Do While arrIndex < 0
                    OddEven()                                                                                  
                    If Num Mod 2 = 1 Then
                        arrIndex = Convert.ToInt16(LettersArray.GetUpperBound(0) * Random1)
                    Else
                        arrIndex = Convert.ToInt16(LettersArray.GetUpperBound(0) * Random2)
                    End If
                Loop
                RandomLetter = LettersArray(arrIndex)
                sb.Append(RandomLetter)
            Else
                ''' GENERATE A RANDOM INDEX IN THE NUMBERS
                ''' CHARACTER ARRAY 
                Do While arrIndex < 0
                    oddEven()
                    If Num Mod 2 = 1 Then
                        arrIndex = Convert.ToInt16(NumbersArray.GetUpperBound(0) * Random1)
                    Else
                        arrIndex = Convert.ToInt16(NumbersArray.GetUpperBound(0) * Random2)
                    End If
                Loop
                sb.Append(NumbersArray(arrIndex))
            End If
        Next
        Return sb.ToString
    End Function

'I added this bit of code to make it just a little bit more random in the chossing 'of the letters or numbers it is called from above and just gets a radom 'number and it will divide by 2 if it is even there will be no remiander else ther 'will be a remainder.

    Private Sub OddEven()
        Randomize()
        Random3 = Rnd()
        Num = Random3 / 2
    End Sub
End Class

Here is the calling code to Get the number or letters.  The intenger after the PinNumbers sets how many characters I require back from the program.

Private Sub GetPin()
               Pin = LCase(dtPin.Rows(0).Item("Init"))
               PinNumbers(3)
               Pin += RandomKey
               PinLetters(1)
               Pin += RandomKey
               PinNumbers(2)
               Pin += RandomKey
End Sub

From the calling code it brings in the number of characters I require and it is passesed by the KeyChars.  The Types tells the program wether it is numbers or letters.

Private Sub PinNumbers(ByVal Number As Integer)
               NumKeys = 1
               KeyGen = New RandomKeyGenerator()
               KeyGen.KeyNumbers = "23456789"
               KeyGen.KeyChars = Number
               KeyGen.Type = "N"
               For i_Keys = 1 To NumKeys
                    RandomKey = KeyGen.Generate()
               Next
End Sub

Private Sub PinLetters(ByVal Number)    
               NumKeys = 1
               KeyGen = New RandomKeyGenerator()
               KeyGen.KeyLetters = "abcdefghijkmnpqrstuvwxyz"
               KeyGen.KeyChars = Number
               KeyGen.Type = "L"
               For i_Keys = 1 To NumKeys
                    RandomKey = KeyGen.Generate()
               Next
End Sub

'As you can see you can pick and choose letters and numbers.  I chose to not 'do 1 and 0 and I and O for the fact that they are easily mistakable for 'eachother.  I use this to automatically come up for a password for our 'employess.  It uses the intials for the first two letters after that it is all the code that does it.