The display may differ according to the operating system or the model of the machine.
On the Windows desktop, double-click the [Canon MF Toolbox 4.9] icon to open the MF Toolbox.
You can also open the MF Toolbox by clicking [start] on the Windows task bar → [(All) Programs] → [Canon] → [MF Toolbox 4.9] → [Toolbox 4.9].
Drag the mark over the button you want to select.
The mark will be displayed above the button you select.
Also you can set it up in the following way.
In the MF Toolbox, click [Settings] to open the [Settings] dialog box. From the drop-down list, select the scanning function you want to link [Start] to, then click [OK].