I tried all the USB ports on my computer, but with the same, negative result. By the way, I bought a new connecting cable, but no difference
Thanks for a variety of suggestions! The camera is about 10 years old, bought originally for my daughter. It has not suffered any of the hazards you mentioned. I tried on a different computer, a laptop with windows Vista but with no success, but that may have been my unfamiliarity with that system. However, almost by chance I tried some newly taken pictures using 'Photo Gallery' on THIS PC, and it worked! So I conclude that the fault may be with the Olympus Master program, despite the fact that until recent months it had been satisfactory. I may try uninstalling the Olympus program & then re-installing from the disc. Thank you for all your help! "Over and out" as radio hams say.