Where have the menus at the top of Excel gone?
 

One set of the spreadsheets which I use have custom menus which import and
export certain templates for data inputting.
These custom menus were developed by somebody else and I have been working
with them for a number of months without problem.
Now, when I open either an existing or a new Excel spreadsheet, I cannot see
the top menu line (File, Edit, Format, Tools etc etc), which means I cannot
work properly.
Can someone help me reinstate the standard menus please?
(I have looked into Help and it explains about displaying toolbars but not
about menus.)
Many thanks