I've bitten the bullet.

I have saved my old Delphi registry sections (just in case...), nuked
those sections of the registry, and re-installed Delphi from scratch
on C drive.

Installed IBO and all is well (have no idea why, but that's life).

Now to re-install those other dozens of components.

Thanks very much for your help Helen and I hope you enjoy Kiri.

Cheers

Peter V.