Sub ConvertDOCtoDOCX_Proper()

    Dim sourceFolder As String
    Dim targetFolder As String
    Dim fileName As String
    Dim doc As Document
    Dim newName As String
    
    sourceFolder = "D:\MyDocFile\"
    targetFolder = "D:\NewDocxFile\"
    
    If Dir(targetFolder, vbDirectory) = "" Then MkDir targetFolder
    
    Application.ScreenUpdating = False
    Application.DisplayAlerts = wdAlertsNone
    
    fileName = Dir(sourceFolder & "*.doc")
    
    Do While fileName <> ""
        
        ' ?? Open in normal mode (IMPORTANT)
        Set doc = Documents.Open( _
                    fileName:=sourceFolder & fileName, _
                    ConfirmConversions:=False, _
                    ReadOnly:=False, _
                    AddToRecentFiles:=False)
        
        ' ?? FORCE full compatibility conversion (MOST IMPORTANT)
        If doc.CompatibilityMode <> wdCurrent Then
            doc.Convert
        End If
        
        ' ?? Force repagination (printer metrics refresh)
        doc.Repaginate
        
        ' ?? New filename
        newName = targetFolder & Replace(fileName, ".doc", ".docx")
        
        ' ?? Save as proper DOCX
        doc.SaveAs2 _
            fileName:=newName, _
            FileFormat:=wdFormatXMLDocument, _
            AddToRecentFiles:=False
        
        doc.Close SaveChanges:=False
        
        fileName = Dir
        
    Loop
    
    Application.DisplayAlerts = wdAlertsAll
    Application.ScreenUpdating = True
    
    MsgBox "All files converted with full compatibility fix!", vbInformation

End Sub