Excel Protect Workbook feature not working

New Contributor

As I have done in the past, I am trying to protect sensitive information via Info/ 'Protect Workbook' /Encrypt with Password. After entering the password twice, it gives me the message 'A password is required to open this workbook'.  When I close the file (after saving changes), file can be opened again without a password.  Thank you for your help!

7 Replies

I figured out what the problem is.  Files saved as .csv apparently cannot be password protected.

best response confirmed by VERONICA LIPPUNER (New Contributor)

Hi Veronica,


Glad to hear that you have figured it out yourself.

I'd like to add that most of Excel functionalities cannot be saved with the .csv file extension!

Because this extension is intended to save raw data only!
It's often used in exporting raw data from some external sources to Excel!




Thank you Haytham!



For anyone else who experiences difficulties with password-protecting Microsoft Office documents in the future:


MS Office does not allow for password protection of documents saved as Open Document Format files.


So if it's a powerpoint save as .pptx or similar, if it's word save as .docx or similar. 


Do not save as .odf and try to password protect.


I just wasted an hour figuring this out; re-installed MS Office and everything.


Microsoft, consider giving users a prompt when password protection is attempted, to prevent this waste of time!

Absolutely right. If its saving as CSV then just have a pop up to say, Hey guys, this wont work with CSV format. Ive already now had to repair my laptop from throwing it across the room in frustration before i found this. Microsoft, you dicks...@Lianne_Abrahams 

Took me 20 minutes to figure this out. Please just add a prompt that you can't encrypt CSV files. This seems like a BIG SECURITY hole since a user might assume the password protection worked.

My problem:  My Excel spreadsheet was created and encrypted using MS Office 2010.  As I have just learned, Microsoft Office 365 which is built into my new HP laptop does not support "password protection." MS 365 automatically migrated all of my other old (password unprotected) Excel files, making them ineligible for encryption. So now, I am left with inability to encrypt any Excel spreadsheet.