I was asked to produce a feature that replaces the author and last modified/saved by document properties of any Word document.
The former is easy enough, and for the latter i figured I could simply change the Office user name, save the file and then restore the user name to its original state.
The below code seems to work just fine for me, but when I tested it on other computers the author was changed but not the last modified by.
Does anyone have any idea why this is? Grateful for any pointers/suggestions on how to sort out the code or reach the same result in another way!

Sub ChangeAuthor()
    Dim Author As String
    Dim orig As String
    Dim Doc As Document
    Author = InputBox("Enter the new document author name.")
    orig = Application.UserName
        With Dialogs(wdDialogFileOpen)
        If .Display Then
            If .Name <> "" Then
                Set Doc = Documents.Open(.Name)
            End If
        Else
            MsgBox "No file selected"
        End If
    End With
    Application.UserName = Author
    With Doc
        .BuiltInDocumentProperties("Author") = Author
        .Saved = False
        .Save
        .Close
    End With
Application.UserName = orig
MsgBox ("Done!")
End Sub