Where can you change automatic or manual collection mode in Excel ?

Double CAL indicator on status bar

Go to File > Options > Formulas > Calculation Option - and mark the corresponding radio button

both

none

Explanation

When you press F9 or click Calc Sheet on the Calculation tab on the Tools/Options menu.

Calculation also occurs every time that you save the file if you have the checkbox "Recalculate workbook before saving" checked under File > Options > Formulas.