You may have to try again. The manual is NOT good, but the information, cryptic as it is, is there. It sends you all over the manual to get all the info. And the Canon implementation of the procedure is unnecessarily complex and officious. Most printer/scanners simply invoke their scanner driver that you install on your computer to scan from the device, so you have all the same options as if you did the scan from the computer. But with Canon you have to set up a totally separate link between the device and a shared folder, ala MS-DOS. It's really primitive and idiotic, and it ain't easy to set up, but it does work.
