How to search content in excel files (without open the files)

Sometimes, we do need to know if we have submitted the particular issue (some word, or numbers) in whole bunches of files. but we can not open the files one by one.
Through Google, a gentleman share his great idea.
I organized by my understanding, and wrote the follow steps:

1) open a file folder

2) click "tool"

 

3) click "folder option"

 

4) click "search", then "always search file names and contents".

5) click "ok".

Now, go to windows explor, click "start", then type the drawing number you're searching for.
See what's happen.