Um, thanks for all these hints and tips. Yes, I have tried:

* system restore (it wouldn't)
* reinstalling the CD driver (didn't fix the problem)
* looking all over the Windows and CD install disks for the specific file (didn't find anything)
* searching on the MS and via Google (ditto)

...and upgrading to XP isn't a runner cos it's an old machine not big enough and not upgradeable enough...

....however! I haven't yet tried:

* installing the MFCD30.DLL which the Villain mailed me (thanks!)
* John in Kansas's idea about the OEM computer maker's website

...and if I can crow-bar my doughter off the PC I'll try (hopefully one but maybe) both of those ideas. Thanks, guys!