Michel take a look into Membership.GeneratePassword Method I think that is what you want.

>I have this code to generate a password with letters and digits:
>
>

>        ' Generate a password
>        ' expN1 Length of the password
>        Public Function GeneratePwd(ByVal tnLength As Integer) As String
>            Dim lcPassword As String = ""
>            Dim lnCounter As Integer = 0
>            Dim lnRandom As Integer = 0
>
>            For lnCounter = 1 To tnLength
>                If lnCounter = 1 Or Int(Rnd() * 100) Mod 2 = 0 Then
>                    lnRandom = Int(Rnd() * 25) + 97
>                Else
>                    lnRandom = Int(Rnd() * 9) + 48
>                End If
>                lcPassword = lcPassword + Chr(lnRandom)
>            Next
>
>            Return lcPassword
>        End Function
>

>
>This code has been converted from VFP. However, this does not work very well in .NET. It practically always generates the same password. Anyone would have something better to recommend?