If you are opening and reopening a spreadsheet attachment from an
e-mail, then you are overwriting your saved spreadsheet with the one
contained in the e-mail. You MUST do a Save AS with the attachment and
save it to a NEW location instead of the temporary folder provided for
VIEWING the attachments.

Rhea wrote:

I always save my spreadsheets when I'm finished inputing data. Almost always,
when I open the spreadsheet back up, data is missing. I spend so much time
going back to find info and puttting it back again. I am not confident my
info is always correct.Help!!