Well, my local guru came round, tried quite a few things with no success. Finally did a Google query, came up with a Microsoft knowledge base help site, which indicated that the problem appears to have come about due to Easy Cd Creator being uninstalled, whioch corrupted a couple of registry files, which he then fixed-(I don't know how- beyond my knowledge base!)

I would not have been able to sort the problem myself. Thanks again to all- as usual, (my knowledge base has been slightly expanded yet again!)