Canon CanoScan N650U Driver and Software

Before you install ScanGear CS-U, make sure that you have accomplished
the following tasks:
• Make sure that the computer is equipped with an enabled USB
port. In My Computer - Control Panel - System icon, click the
Device Manager tab and double-click “Universal serial bus
controler”. If you can see the names of the Host Controller and
USB Root Hub displayed, the computer is equipped with an
enabled USB port. Some computers may require enabling the USB
function with a BIOS setting. For details about enabling the USB
port with the BIOS setting, see your computer manual.
• Make sure the scanner is connected to a computer.
• If a previous version of ScanGear CS is installed on your computer,
uninstall it before you install ScanGear CS-U 5.7.
Note
• With Windows 2000 Professional, ensure that you log on
as an Administrator to install/uninstall the software.
• If ScanGear CS-U has already been installed according to
the instructions in the Getting Started guide that came
with the scanner, there is no need to perform the
installation procedures described on the following pages.

To get the driver you need to make sure what is your OS (operating system) in your PC. e.g. window XP, vista, Window 2000 etc.
If you do not have the CD/disk you can download here and run the executable file. Follow the instruction.

You can get details user guide  for N650U, N656U, N1220U here