Better to show use more of the code that you are using.
However, you can definitely use something like
Dim mydoc as Document
Set mydoc = Documents.Open("Path\Filename")
mydoc.Activate
In the above situation, no need to use Windows()
Of course, when you open a document, it is by default the active document, but your code could be
Dim Doc1 as Document, Doc2 as Document
Set Doc1 = Documents.Open("Path\Filename")
Set Doc2 = Documents.Add
in which case Doc2 would be the active document. So if you wanted to make Doc1 the active document, you would use
Doc1.Activate
In many situations however, it is not necessary to activate the document, particularly if you use the .Range object rather than the .Selection object.
