Dim Directory = Application.StartupPath + "orders"
Dim Files() As System.IO.FileInfo
Dim DirInfo As New System.IO.DirectoryInfo(Directory)
Dim StrClean As String

Sub ShowFiles()

    Files = DirInfo.GetFiles("*.xml", IO.SearchOption.TopDirectoryOnly)
    For Each File In Files
        lstFiles.Items.Add(File)
    Next
End Sub