Download Driver Updater Pro to get the most current drivers for your computer.
You can download driver for Canon CanoScan 300/600 ScanGear Toolbox CS 2.2.3 here, but DriversKit`s Team strongly recommend you to use Driver Updater Pro for finding latest version of this driver. You can download Driver Updater Pro here.
Also you can:
Search Canon CanoScan 300/600 ScanGear Toolbox CS 2.2.3 driver at Google