Dim wBk As Workbook
Dim sFileSpec As String
Dim sPathSpec As String
Dim sFoundFile As String

sPathSpec = "J:Secure Downloads"
sFileSpec = "*.xl*"

sFoundFile = Dir(sPathSpec & sFileSpec)
Do While sFoundFile <> ""
    Set wBk = Workbooks.Open(sPathSpec & sFoundFile)
    With wBk
        Application.DisplayAlerts = False
        wBk.SaveAs Filename:=.FullName, _
          Password:="summer"
        Application.DisplayAlerts = True
    End With
    Set wBk = Nothing
    Workbooks(sFoundFile).Close False
    sFoundFile = Dir
Loop