When someone tells you that formulas aren’t calculating, it’s probably because the Calculation setting has been changed to Manual, instead of Automatic. That can happen if the first workbook that you open in an Excel session was saved as Manual calculation. That setting affects all the other workbooks the you open during that session.
In this case, the workbook calculation was set to Automatic on all the machines – that’s the first thing we checked. To check the setting, click the Formulas tab on the Excel Ribbon, and click the Calculate Options drop down.
Or, go to the Excel Options window, and click Formulas.