Scanner Doesn't Work
Windows 2003 Server

- The WIA driver works fine. The scanner can complete the device test OK, and I even hear the scanner head moving, so I *know* it's not a USB/hardware/communication/driver/etc. problem.

- When I try to scan from any app that has TWAIN support I get a 'no devices installed' type error.

- My scanner has buttons. The buttons show up as mappable to application launches in the WIA control (in Scanners and Cameras folder).

- To edit the list of apps (and add any arbitrary one you like), use regedit and add them in
<HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\StillImage\Registered Applications>.

- Then, map the app to the scanner button and press it.

Now, when I press the scan button on the scanner, it launches my app with the TWAIN driver loaded and fully accessible -- the actual one that came with my scanner, not just the crappy WIA one. Apparently, you don't even need to have an app that supports command line scanner switches (as the ones that show up in that list normally do); windows will sense the button-press and somehow magically make the TWAIN driver accessible.