You could also try switching the scanner on BEFORE switching on your PC as Peripherals powered up after the computer are not guaranteed to be recognised and access will therefore be denied. In this case, there's little option but to do a restart with all the peripherals switched on.
Try opening the folder containing the software, right-clicking on the Setup file, clicking Properties, in the Properties window clicking the Compatibility tab, checking the little square next to "Run this program in compatibility mode for:", selecting "Windows XP (service Pack 2)" from the drop-down list (if it is not already displayed), clicking Apply and OK, then running the Setup file.
However, this is a workaround which may or may not work.
There are a few suggestions here also - see one's from "M Sin" and "Leo Lazcarez" - may work - worth a try.
I actually got my scanner to work (Canon Canoscan 8600F) in Windows 7 64 bit by installing driver software in Windows XP Virtual Machine XP Mode - I was then able to run it from "Devices & Printers" in Windows 7