Win 2000 professional install problems

I recently used some helful advice on a previous enquiry and did an in-pace reinstallation of Windows 200 professional.

As was predicited the system then accessed the microsoft update site and upgraded to Service Pack 4.

Unfortunatelt the newly-istalled system still exhibited the problems I was trying to cure.

I tried exploring other install options from the original CD-ROM. However I got a message saying that I could not re-install SP2 (as per the CD) after having upgraded to SP4!

The main underlying problem is in using the Registered Applications window ehn hot-plugging an imaging device. The "selection" window appears but the contents are empty.

Does anyone know if there is an easy fix for this (re-installing the TWAIN software interfaces has no effect).

Using microsoft's own terminoloy "Registered Applications" does not produce anyting from the microsoft knowledge base.

I fear I may have to re-install from scratch and laboriously re-install all the applications!