[RESOLVED] Folder Looping Problem

[DataHunter2009]

Hello, I'm working on a new version of my old SecureMD5 program (which you may have seen on download.com or softpedia). One of the new features is Recursive Generation.

The program loops through each file in a folder and generates a checksum for it. Then it places the checksums in a file.

The only problem is... nothing happens. I click Generate, and the programs just sits there and does nothing. Here's my code for the Generate button:

Try
                    Dim dir As New System.IO.DirectoryInfo(TextBox7.Text)
                    Dim md5 As New System.Security.Cryptography.MD5CryptoServiceProvider
                    Dim hash As Array
                    Dim i As Integer
                    Dim files As Array
                    Dim sb As New System.Text.StringBuilder
                    files = dir.GetFiles
                    For i = files.Length To files.GetUpperBound(0)
                        Dim f As New System.IO.FileStream(i.ToString, IO.FileMode.Open)
                        md5.ComputeHash(f)
                        hash = md5.Hash
                        For Each hashByte As Byte In hash
                            sb.Append(String.Format("{0:X1}", hashByte))
                        Next
                        System.IO.File.AppendAllText(TextBox8.Text, sb.ToString)
                        f.Close()
                    Next
                Catch ex As Exception
                    MessageBox.Show("An error occured while trying to generate a checksum!" & Environment.NewLine & ex.Message, "Error!", MessageBoxButtons.OK, MessageBoxIcon.Error)
                End Try

TextBox7 is the textbox for the folder path and TextBox8 is the textbox for the output file (with the checksums). Just thought you might need to know that.