I need a way to halt an Excel Procedure "Private Sub Workbook_Open()" to use as needed

I have a workbook that is scheduled to run using MS Scheduled tasks. The code is inside this Workbook open and the file has digital signatures so no pop ups come up.
My problem is when I want to make a change and don't want any code exectued at start.
I thought I could hold the shift key down to disable the macro but it runs one loop and sends mail before stopping.

Is there something I am missing or another way to look at this?
There is a snip of code below as an example. I actually mail 28 files with the code and only included a short sample.

Private Sub Workbook_Open()
'This procedure Below will mail copies of the specific books.
    Dim wb As Workbook
    Dim TempFilePath As String
    Dim TempFileName As String
    Dim FileExtStr As String
    Dim iMsg As Object
    Dim iConf As Object
    '    Dim Flds As Variant

'MAIL # 1++++++++++++++++++++++++++++++++++++++++++++++++++++
    ChDir "Q:\MIS\Aspect\Daily"
    Workbooks.Open Filename:="Q:\MIS\AspectIV\CCSC 452 - Current Customer.xls"

    Set wb = ActiveWorkbook
    With Application
        .ScreenUpdating = False
        .EnableEvents = False
    End With

  'Make a copy of the file/Mail it/Delete it
    TempFilePath = Environ$("temp") & "\"
    TempFileName = wb.Name & " " & Format(Now - 1, "dd-mmm-yy")
    FileExtStr = "." & LCase(Right(wb.Name, Len(wb.Name) - InStrRev(wb.Name, ".", , 1)))
    wb.SaveCopyAs TempFilePath & TempFileName & FileExtStr

    Set iMsg = CreateObject("CDO.Message")
    Set iConf = CreateObject("CDO.Configuration")
    With iMsg
        Set .Configuration = iConf
        .To = "Hele.com"
        .CC = ""
        .BCC = "mitch.com"
        .From = "MrDa.com"
        .Subject = "This is an automated mailing of report ccsc_452.xls"
        .TextBody = "comments, Please Email Mitch."
        .AddAttachment TempFilePath & TempFileName & FileExtStr
        .Send
    End With
         Kill TempFilePath & TempFileName & FileExtStr

    With Application
        .ScreenUpdating = True
        .EnableEvents = True
    End With
ActiveWorkbook.Save
ActiveWindow.Close

'MAIL # 2++++++++++++++++++++++++++++++++++++++++++++++++++++
    ChDir "Q:\MIS\Aspect\Daily"
    Workbooks.Open Filename:="Q:\MIS\AspectIV\CCSC 454 - Current.xls"
   Set wb = ActiveWorkbook
    With Application
        .ScreenUpdating = False
        .EnableEvents = False
    End With

  'Make a copy of the file/Mail it/Delete it
    TempFilePath = Environ$("temp") & "\"
    TempFileName = wb.Name & " " & Format(Now - 1, "dd-mmm-yy")
    FileExtStr = "." & LCase(Right(wb.Name, Len(wb.Name) - InStrRev(wb.Name, ".", , 1)))
    wb.SaveCopyAs TempFilePath & TempFileName & FileExtStr

    Set iMsg = CreateObject("CDO.Message")
    Set iConf = CreateObject("CDO.Configuration")
    With iMsg
        Set .Configuration = iConf
        .To = "helre.com"
        .CC = ""
        .BCC = "mitccom"
        .From = "MrDacom"
        .Subject = "This is an automated mailing of Aspect report ccsc_454.xls"
        .TextBody = " comments, Please Email Mitch."
        .AddAttachment TempFilePath & TempFileName & FileExtStr
        .Send
    End With

   Kill TempFilePath & TempFileName & FileExtStr

    With Application
        .ScreenUpdating = True
        .EnableEvents = True
    End With
ActiveWorkbook.Save
ActiveWindow.Close
 End Sub()Start Free Trial