Primary workbook is hidden when name of hidden workbook changes

Hi,

I have a file PQR.xlsm. When it opens, I want 'ABC.xlsx' and 'Std XYZ.xls', which are saved on a shared drive,to open as well, but remain hidden from view. This is because I have some vba code that does vlookup in PQR based on values in ABC and XYZ. So when I open PQR, all 3 workbooks open, but only PQR is visible.When PQR is closed, I want ABC and XYZ to close without save prompt. I managed to put this code together(after going thru some forums) that does what I want. However, last evening 'Std XYZ.xls' was changed to 'XYZ.xlsx'. When I tried opening PQR, all 3 were hidden. I went into vba and updated 'Std XYZ.xls' to 'XYZ.xlsx', but it wouldnt work. Can someone help me figure out why that is?

When I have ActiveWorkbook.Windows(1).Visible = False, what is windows(1)?
Is there a windows 2, 3 etc?

Below is the code pasted in the 'ThisWorkbook' Excel Objects.

Private Sub Workbook_BeforeClose(Cancel As Boolean)
Workbooks("ABC.xlsx").Saved = True
Workbooks("XYZ.xlsx").Saved = True
End Sub

Private Sub Workbook_WindowActivate(ByVal Wn As Window)
Dim wBook As Workbook
Dim wBook1 As Workbook
                
    On Error Resume Next
    Set wBook = Workbooks("ABC.xlsx")
    Set wBook1 = Workbooks("XYZ.xlsx")
     
    If wBook Is Nothing Then
        ChDir "T:\"
        Set wBook = Workbooks.Open(Filename:="\\DM0001.ABC.xlsx", ReadOnly:=True)
        ActiveWorkbook.Windows(1).Visible = False
    Else
    If wBook1 Is Nothing Then
    Set wBook1 = Workbooks.Open(Filename:="\\DM0001.XYZ.xlsx", ReadOnly:=True)
   ActiveWorkbook.Windows(1).Visible = False
     End If
     End If
      ThisWorkbook.Activate
        Worksheets("Instructions").Select
         
   
End Sub

I was wondering if you had taken the time whilst waiting to read the Form Rules.

Your post does not comply with Rule 1 of our Forum RULES. Your post title should accurately and concisely describe your problem, not your anticipated solution. Use terms appropriate to a Google search. Poor thread titles, like Please Help, Urgent, Need Help, Formula Problem, Code Problem, and Need Advice will be addressed according to the OP's experience in the forum: If you have less than 10 posts, expect (and respond to) a request to change your thread title. If you have 10 or more posts, expect your post to be locked, so you can start a new thread with an appropriate title.
To change a Title on your post, click EDIT then Go Advanced and change your title, if 2 days have passed ask a moderator to do it for you.