From workbook press Alt+F11 to launch VBE (Visual Basic Editor). From the
left treeview search for the workbook name and click on + to expand it.
Within that you should see the following
VBAProject(Your_Filename)
Microsoft Excel Objects
Sheet1(Sheet1)
Sheet2(Sheet2)
Sheet3(Sheet3)
This Workbook
Double click 'This WorkBook' and paste the below code to the right code pane.
Private Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, Cancel As Boolean)
Msgbox "Cannot Save"
'to cancel the save
Cancel = True
End Sub
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