Run Code on all files and save files as .docx

[macropod]

Try:

Sub UpdateDocuments()
Application.ScreenUpdating = False
Dim strFolder As String, strFile As String, wdDoc As Document
strFolder = GetFolder
If strFolder = "" Then Exit Sub
strFile = Dir(strFolder & "\*.doc", vbNormal)
While strFile <> ""
  Set wdDoc = Documents.Open(FileName:=strFolder & "\" & strFile, AddToRecentFiles:=False, Visible:=False)
  Call DDS(wdDoc)
  With wdDoc
    .SaveAs2 FileName:=strFolder & "\" & Split(strFile, ".")(0) & ".docx", FileFormat:=wdFormatXMLDocument, AddToRecentFiles:=False
    .Close SaveChanges:=False
  End With
  strFile = Dir()
Wend
Set wdDoc = Nothing
Application.ScreenUpdating = True
End Sub
 
Function GetFolder() As String
Dim oFolder As Object
GetFolder = ""
Set oFolder = CreateObject("Shell.Application").BrowseForFolder(0, "Choose a folder", 0)
If (Not oFolder Is Nothing) Then GetFolder = oFolder.Items.Item.Path
Set oFolder = Nothing
End Function
 
Sub DDS(wdDoc As Document)
With wdDoc.Range
  .Font.Shrink
  .Font.Shrink
  With .PageSetup
    .Orientation = wdOrientLandscape
    .LineNumbering.Active = False
    .TopMargin = InchesToPoints(0.5)
    .BottomMargin = InchesToPoints(0.5)
    .LeftMargin = InchesToPoints(0.5)
    .RightMargin = InchesToPoints(0.5)
    .Gutter = InchesToPoints(0)
    .HeaderDistance = InchesToPoints(0.5)
    .FooterDistance = InchesToPoints(0.5)
    .PageWidth = InchesToPoints(11)
    .PageHeight = InchesToPoints(8.5)
    .FirstPageTray = wdPrinterDefaultBin
    .OtherPagesTray = wdPrinterDefaultBin
    .SectionStart = wdSectionNewPage
    .OddAndEvenPagesHeaderFooter = False
    .DifferentFirstPageHeaderFooter = False
    .VerticalAlignment = wdAlignVerticalTop
    .SuppressEndnotes = False
    .MirrorMargins = False
    .TwoPagesOnOne = False
    .BookFoldPrinting = False
    .BookFoldRevPrinting = False
    .BookFoldPrintingSheets = 1
    .GutterPos = wdGutterPosLeft
  End With
End With
End Sub