To password protect a Microsoft Word document, you can follow these steps:

1. Open the Word document that you want to password protect.
2. Click on the “File” tab in the top left corner of the screen.
3. From the dropdown menu, select “Protect Document” and then click on “Encrypt with Password.”
4. A dialog box will appear, prompting you to enter a password. Choose a strong password that is easy for you to remember but difficult for others to guess. Make sure to use a combination of uppercase and lowercase letters, numbers, and special characters for better security.
5. After entering the password, click on the “OK” button. A confirmation dialog box will appear, asking you to reenter the password to confirm it. Re-enter the same password and click “OK.”
6. The document is now password protected. Whenever someone tries to open the document, they will be prompted to enter the password.
7. Save the document to apply the password protection. You can now close the document, and the password protection will remain in place.

Remember to keep your password in a safe place or use a password manager to ensure you don’t forget it, as there is no official way to recover a lost password for a Word document.