Frank's code will actually count the number of times the workbook has been
opened AND saved.
If the workbook is closed without saving, then that change goes away.
If the workbook is "saveable" (not readonly), then you could save it as soon as
it opens:
A minor tweak to Frank's code:
Private Sub Workbook_Open()
with Worksheets("Sheet1").range("A1")
.Value = .Value + 1
end with
me.save
End Sub
If you can't save the workbook, then maybe you could use an external (accessible
(read/write) by all who open it to keep a counter.