Maybe a little bit late for you, but maybe of interest for other people who run into the same problem:
I had the same problem. I found a link for a driver on this page: http://www.webwhitenoise.com/item/20...0-x64-drivers/
I installed the driver and the scanner was recognized (its a non official driver which is not verified, so I do not know if it is dangerous to install).
After that you have to install the toolbox (canoscantoolbox) form the website.
Do not install a new version (e.g. 4.9) because this will give an error when scanning (invalid twain). Download the software 4.1 version from the canon site.
My scanner is up and running again.
I hope this will help other people who do not like to throw away good working devices because the manufacturer will not develop a new driver for it (this was almost my second scanner I have to throw away because of a new os).
Canon says the scanner cannot communicate in windows 7. It can.