1 I had read many entries on the forum.
2. I retried YAST > Boot loader AFTER I mounted the visible Acer Vista hard disc (it is detected but not mounted on normal SUSE screen or in file loader)
3 I then re-ran the boat loader twice.
4. Success achieved. It loaded the normal VISTA start in GRUB 2 boot menu.
5. so both systems now:
openSUSE12.3 has default , normal and recovery systems available
windows VISTA has recovery and normal systems available.
6 Back to normal for selection of this dual boot machine.
However, it would be appreciated if someone would advise how to edit GRUB 2 if this had not worked.
(Editing legacy grub was easy, but I have no knowledge and forums etc on GRUB 2 seem very complex)