Scanner quit on Win7 but still ok on Linux

[Circlotron]

3-1/2 years ago I got a Canon LIDE 210 for myself and an LIDE 110 for my mum. Hers has been working fine up until now. Since the other day though, if you push the "copy" button on the scanner the scanner starts moving and the progress bar only goes partway and then quits and displays an error message about not being able to communicate with the scanner. If I open Control Panel, select the scanner icon and right click "scan" then it does actually scan with the option to save the image. The thing is, it has to be a mum-friendly one-button operation straight to the printer.

Tried a new USB cable. Nuh. Removed, downloaded and reinstalled scanner driver and MP Navigator (scanning options dashboard thingy). Still no good. Put my scanner and driver and MP Navigator and all went well. THEN.... I took her scanner home and plugged it into my Linux Mint system and used xsane it worked just fine and dandy! I'm at a loss as to what might have gone wrong with the Win7 system, especially seeing that reinstalling the driver didn't fix it but a slightly different driver and different scanner from the same manufacturer (both from same product family, not very different at all) was okay. Any ideas?