Yeah, so you automatically got the newest driver for your Canoscan when upgrading to Windows 7. However, when you go into Photoshop CS5, you no longer see TWAIN devices listed(!). Unfortunately, in Adobe’s infinite wisdom, they have discontinued installing TWAIN support by default. You need to go here:
to download the ‘Photoshop CS5 Optional Plugins’ free download.
Edit: Note – this ONLY works with 32-bit version of Photoshop CS5. There still is no TWAIN support on 64-bit Photoshop.
Unzip the file, then copy
Twain_32.8BA from the zip’s
directory, and copy it into your Photoshop CS5 32-bit plugins folder:
C:Program Files (x86)\Adobe\Adobe Photoshop CS5\Plug-ins\
directory. Restart Photoshop and you should see your TWAIN capture option again.