I use the following to turn off the calculation and then
back on when exiting my workbook.

Private Sub Workbook_Activate()
Application.Calculation = xlManual
Application.CalculateBeforeSave = False
End Sub

Private Sub Workbook_Deactivate()
Application.Calculation = xlAutomatic
Application.CalculateBeforeSave = True
End Sub

When I open only one workbook at a time it works fine but
when I open a second workbook with the same code it
starts to calculate also everytime I close my workbook it
asks if I want to save the changes. Is there a way to not
calculate when a second workbook is opened with the same
code and to not ask if I want to save changes unless I
have made changes?

TIA
Joe