To password protect an Office document, first open it in Word, Excel, PowerPoint, or Access. Click the “File” menu at the top-left corner of the screen. On the Info pane, click the “Protect Document” button and select “Encrypt with Password.”

The button is only named “Protect Document” in Microsoft Word, but it’s named something similar in other apps. Look for “Protect Workbook” in Microsoft Excel and “Protect Presentation” in Microsoft PowerPoint. In Microsoft Access, you’ll just see a an “Encrypt with Password” button on the Info tab. The steps will otherwise work the same.

NOTE: If you only want to restrict editing of the document, you can choose “Restrict Editing” here, but as we said, that is not very secure and can easily be bypassed. You’re better off encrypting the entire document, if you can.

Enter the password you want to encrypt the document with. You’ll want to choose a good password here. Weak passwords can be easily guessed by cracking software if someone gains access to the document.

Warning: You’ll lose access to the document if you ever forget your password, so keep it safe! Microsoft advises you write down the name of the document and its password and keep it in a safe place.

When a document is encrypted, you’ll see the “A password is required to open this document” message on the Info screen.

The next time you open the document, you’ll see an “Enter password to open file” box. If you don’t enter the correct password, you won’t be able to view the document at all.

To remove the password protection from a document, click the “Protect Document” button and select “Encrypt with Password” again. Enter a blank password and click “OK.” Office will remove the password from the document.