Dim FileName As String = "Modellofogliointervento.dotx"
        Dim path As String = "C:\...\Modellofogliointervento.dotx"

        Response.Clear()
        Response.Buffer = True
        Response.ContentType = "application/vnd.ms-word"
        Response.AppendHeader("Content-Disposition", "attachment; filename=Modellofogliointervento.dotx")   <--- Mancava questa riga
        Response.TransmitFile(path)
        Response.End()