Hi!
My PC is Win98 SE and my scanner CanoScan N670U. 
I received this message when trying to reinstall the CanoScan driver:

?STIMON caused an invalid page fault in module NO67UFW.DLL at
0177:03321952? (?STIMON? is the file stimon.exe)

The PC would no longer recognize the scanner. MS Support gives a
lengthy and difficult instruction for repair of stimon.exe, including
renaming the file etc., too complicated for me. I shut down,
reconnected the scanner, followed instructions in the Canon Booklet
and ended up with the message: Install the TWAIN_32 drivers. From then
on I go in circles.
My PC shop has tried all and now wants to reformat which I would rather not.
Can anyone help? I would be much obliged.

Regards, Casso

Try following the following steps, this should solve it:
- Unplug the scanner
- Uninstall its drivers from the system. (Control panel->System)
- Uninstall any related software that came with it.(Start->Programs->AllRelated)
- Reboot (The reset button ;) )
- Insert your CD and perform a clean install of drivers for the device.