NAC Inc and TCS - many thanks for your help. I have at last plunged and made a move after weighing up all the points! I decided to plump for TCS' CMD and restore which worked after I had figured out where to type CMD! I now have everything back except for my address book . I decided against a reinstall just before the Christmas period as that would involve resetting my cable internet programme , probably leaving me incomunicado for a week or so ! Relief all round and address books can be rewritten over time.
Many thanks again guys and a Merry Christmas to all!