Failed load of Plug and Play

IBM Thinkpad T20 with windows 98se
After an F Disk ther was always one device that couldn't be identified but
the PC seemed to work well enough.
Recently had problems that cumulated in the 3com 10/100 mini PCI ethernet
adaptor not working properly with an unidentified fault.
Fixed the missing device at last (Power Management) but left with an
annoying set of problems including another unrecognised device (PCI simple
communications device) and a boot up problem "Resource conflict - PCI Bus:00,
Device:03, Function: 01.
Couldn't figure out why the device wasn't being recognised.
IBM detected some missing drivers and loaded all but the driver for the 3com
mini pci adapter which it says it has loaded but it always reappears in the
installation program as required and not installed.
ABout this time i noticed that Plug and play software device enumerator
wasn't there under system devices. Used the add hardware but this hangs when
it gets to copying devices. With some patience it does finally seem to see
the CD to load but PNP never appears in the device list.
I did try the "have disk" approach with copied machine.inf but couldn't find
more than a passing reference to this method. Besides, machine .inf says
[detect.devinfs]
*pnpOAOO=machine2.inf etc.
Any ideas?