If you use Windows XP or below you can go to Start > Control Panel > Add or Remove Programs. In the Currently installed programs box, click on the ScanGear Starter program and then click Remove.
If you have Windows Vista or above you need to go to Start > Control Panel > Programs > Programs and Features. Select the ScanGear Starter application and click on Uninstall.
After that, go to Start > Control Panel > Hardware and Sound > Device Manager, expand the Universal Serial Bus controllers, Imaging Devices or Printers lists and locate your old printer driver. Right-click on its driver and select Uninstall. After that, reboot your computer, run a registry cleaner to make sure that there are no leftover rogue registry keys in your system and reinstall the ScanGear Starter software. If you no longer have the installation package, you can download and install it from Canon Downloads page.