I think it's Tools / Options / Edit / Enable Autocomplete for Cell Values

turn off that checkbox.

"jayceejay" wrote:

Please HELP. I am entering strings of numbers for street adresses, such as
"137th" or "73rd" and when I advance to the next cell, Excel is automatically
and INCORRECTLY CHANGING these entries to "137Th" and "73Rd". I cannot find
which auto correct feature or other option is doing this to me and it is
driving me crazy. Could someone help me find what I need to shut off?

Jay