The "Imaging Devices" category in Device Manager will return when your
scanner's driver is installed. Empty categories aren't shown. Your only
problem so far is getting the driver for your scanner installed...
As far as usbscan.sys goes, look under
C:\Windows\System32\DriverStore\FileRepository\ for a folder beginning with
sti.inf_...
"rjk42" <(E-Mail Removed)> wrote in message
news

2A38BA8-B45F-4C36-8241-(E-Mail Removed)...
> The Device Manager no longer shows "Imaging Devices" as one of the
> available
> device types. It's very likely my fault, and I don't know how to fix it.
>
> I was struggling to get a Canon flatbed scanner to work with my new
> desktop
> system (a separate problem). Following directions from Canon technical
> support, I opened device manager, found the scanner listed under "Imaging
> Devices", right clicked, then clicked "Uninstall".
>
> I seem to have uninstalled more than just the scanner, however - that's
> the
> point at which "Imaging Devices" disappared.
>
> Now, when I plug in the scanner (which still doesn't work), it comes up
> under "unknown devices".
>
> Also, Canon tech support had me search for usbscan.sys, which does not
> seem
> to be anywhere on my hard drive (this was after the accident with the
> Device
> Manager.)
>
> so, how badly did I mess up?