This example turns off screen updating, opens Test.doc, inserts text, refreshes the screen, and then closes the document (with changes saved).
ScreenUpdating = False
Documents.Open FileName:="C:\DOCS\TEST.DOC"
Set myRange = ActiveDocument.Range(Start:=0, End:=0)
myRange.InsertBefore "new"
Application.ScreenRefresh
ActiveDocument.Close SaveChanges:=wdSaveChanges
ScreenUpdating = True