Remove the checkmark from the Use default checkbox.
Enter a number into the Maximum undo steps per VI text box. The maximum number you can enter is 99. Enter 0 to disable Undo and Redo.
Note Each VI records its own undo instances. Therefore, the number you enter for Maximum undo steps per VI pertains to each VI. Setting this number low can conserve memory resources.
In some instances, LabVIEW deletes all undo information. VI callers automatically update when the VI changes its front panel. LabVIEW deletes all undo information in caller VIs when you make the following changes: