I have install this excel program for almost 10 yrs now and been working fine until last week... I was working on a September program book that I save my work day on everyday and I do back up at the end of the month... on September 15 I tried to open my book and the book is nowhere to be find .I did the window search and it find a book that is located in a different folder, and no September work on it... did I loose my September for good... and what should I do to start all over again... thank you all

If you can't find the file you created, it somehow got lost. Sounds like you will need to recreate. Don't you do backups?