Saved from a previous post:
For brand new workbooks, you could create a book.xlt workbook template (stored
in your XLStart folder) that has each window the way you want.
If you want existing workbooks, then ...
Create a new workbook.
Add this code to the ThisWorkbook module:
Option Explicit
Public WithEvents xlApp As Application
Private Sub Workbook_BeforeClose(Cancel As Boolean)
Set xlApp = Nothing
End Sub
Private Sub Workbook_Open()
Set xlApp = Excel.Application
End Sub
Private Sub xlApp_NewWorkbook(ByVal Wb As Workbook)
Call DoTheWork(Wb)
End Sub
Private Sub xlApp_SheetActivate(ByVal Sh As Object)
Call DoTheWork(Sh.Parent)
End Sub
Private Sub xlApp_WorkbookOpen(ByVal Wb As Workbook)
Call DoTheWork(Wb)
End Sub
Private Sub DoTheWork(Wb As Workbook)
Dim myWindow As Window
For Each myWindow In Wb.Windows
myWindow.Zoom = 75
Next myWindow
End Sub
Save this file as an addin in your XLStart folder.
Each time you create a new workbook, open an existing workbook, change to a new
sheet, it'll set the zoom to 75%.
If you're new to macros, you may want to read David McRitchie's intro at:
http://www.mvps.org/dmcritchie/excel/getstarted.htm
You can read a lot more about application events at Chip Pearson's site:
http://www.cpearson.com/excel/AppEvent.htm