Re: mptwain.dll ???
MPTWAIN.dll: MP=Multipass. Twain is in the scan gear folder for some Canon Multifuntion Printers like the Canon C755.
Try your PROGRAMS\CANON\SCANGEAR folder if you are using a canon multifunction printer.
If you need the file you should be able to download it from Canon America's web site.
The last version, I believe was 126.96.36.199 used with Win 2000 or ME. I'm guessing it won't work with XP unless you run it as a Win 98 file.
Hope that helps.