Option Explicit
Dim FSO As Object, oFolder As Object, StrFolds As String
 
Sub Main()
Application.ScreenUpdating = False
Dim TopLevelFolder As String, TheFolders As Variant, aFolder As Variant, i As Long
TopLevelFolder = GetFolder
StrFolds = vbCr & TopLevelFolder
If FSO Is Nothing Then
  Set FSO = CreateObject("Scripting.FileSystemObject")
End If
'Get the sub-folder structure
Set TheFolders = FSO.GetFolder(TopLevelFolder).SubFolders
For Each aFolder In TheFolders
  RecurseWriteFolderName (aFolder)
Next
'Process the documents in each folder
For i = 1 To UBound(Split(StrFolds, vbCr))
  Call UpdateDocuments(CStr(Split(StrFolds, vbCr)(i)))
Next
Application.ScreenUpdating = True
End Sub
 
Sub RecurseWriteFolderName(aFolder)
Dim SubFolders As Variant, SubFolder As Variant
Set SubFolders = FSO.GetFolder(aFolder).SubFolders
StrFolds = StrFolds & vbCr & CStr(aFolder)
On Error Resume Next
For Each SubFolder In SubFolders
  RecurseWriteFolderName (SubFolder)
Next
End Sub

Sub UpdateDocuments(oFolder As String)
Dim strFolder As String, strFile As String, wdDoc As Document
strFile = Dir(strFolder & "\*.docx", vbNormal)
While strFile <> ""
  Set wdDoc = Documents.Open(FileName:=strFolder & "\" & strFile, AddToRecentFiles:=False, Visible:=False)
  With wdDoc
    Call RefreshFields(wdDoc)
    'Optional - create a PDF of the updated document
    '.SaveAs2 FileName:=Split(.Fullname, ".doc")(0) & ".pdf", FileFormat:=wdFormatPDF, AddToRecentFiles:=False
    .Close SaveChanges:=True
  End With
  strFile = Dir()
Wend
Set wdDoc = Nothing
End Sub

Sub RefreshFields(wdDoc As Document)
Dim oStory As Range, oTOC As TableOfContents, oTOF As TableOfFigures
With wdDoc
  For Each oStory In .StoryRanges
    oStory.Fields.Update
    If oStory.StoryType <> wdMainTextStory Then
      While Not (oStory.NextStoryRange Is Nothing)
        Set oStory = oStory.NextStoryRange
        oStory.Fields.Update
      Wend
    End If
  Next oStory
  For Each oTOC In .TablesOfContents
    oTOC.Update
  Next oTOC
  For Each oTOF In .TablesOfFigures
    oTOF.Update
  Next oTOF
End With
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