This is a setting of Excel, not of your files.
ToolsOptionsGeneral, uncheck R1C1 Reference style

--

Kind Regards,

Niek Otten

Microsoft MVP - Excel

"garyflood" wrote in message
...
For some reason all my excel files now display columns as numbers rather
than
letters. How can I change back to letters? Why are all my old files also
now reading in numbered columns?