Built-in scanner driver is missing

Archived from groups: microsoft.public.windowsxp.hardware (More info?)

Hello:

I have an HP 6250cse scanner that I have been using successfully for a
long time under Windows XP by using a TWAIN driver supplied by HP.
However, now I have a development project that requires me to install a
Windows Imaging Acquisition (WIA) driver for this same scanner.

I have two Windows XP-based computers that are able to silently
recognize and install the WIA drivers for this device, and the scanner
works on those computers without any hassle at all.

But on my development computer, where I really _need_ it to work, I
cannot get the WIA driver to install. I have followed HP's instructions
to thoroughly remove the original TWAIN driver, and I have restarted
Windows XP. It correctly recognizes the scanner, but then Windows tries
to search for a driver, and is unable to find one.

If I go to one of the other computers that correctly supports the
scanner, and look at the driver details, I see that the WIA driver for
this scanner consists of hpsjmcro.dll, usbscan.sys, and wiafbdrv.dll.

If I go to the computer that isn't working, I see that all three of
those files are already present, in the expected locations.

So, the challenge is convincing Windows that it ought to make the
connection between my scanner and the driver that is already present.

If I go through Control Panel->Scanners and Cameras->Add Device, and
select my way through to HP, there are only three available devices
listed, all of which are cameras, not scanners. I find this odd, since
the knowledge base article Q293356 has quite a long list of HP devices
that are supported by built-in WIA drivers. Why don't these other
devices appear? (They don't appear on the two computers that are
working correctly, either.)

I have already done an sfc /scannow just in case my DLL cache was
screwed up. This had no beneficial effect.

Can anyone tell me why this one computer is unable to find the built-in
driver for this scanner?

Thank you for your time,
Tim Crews
GECO, Inc.