hi can someone help me with the code for renaming existing files? thanks alot!

this is what ive wrote.. and it fails to rename existing files
Code:
             For Each file As String In listbox1.Items
                    IO.File.Copy(file, IO.Path.Combine(fbCopyto.SelectedPath, IO.Path.GetFileName(file)))
                    While IO.File.Exists(fbCopyto.SelectedPath & file)
                        file=  file & x & ".wav"
                        x += 1


                    End While
                Next