Security Use strong passwords that combine uppercase and lowercase letters, numbers, and symbols. Weak passwords don't mix these elements. Strong password: Y6dh!et5. Weak password: House27. Passwords should be 8 or more characters in length. A pass phrase that uses 14 or more characters is better. For more information, see Help protect your personal information with strong passwords.It is critical that you remember your password. If you forget your password, Microsoft cannot retrieve it. Store the passwords that you write down in a secure place away from the information that they help protect.
- Open the file.
- On the Tools menu, click Options, and then click Security.
- Do one of the following:
Create a password to open
- In the Password to open box, type a password, and then click OK.
- In the Reenter password to open box, type the password again, and then click OK.
Create a password to modify
- In the Password to modify box, type a password, and then click OK.
- In the Reenter password to modify box, type the password again, and then click OK.
To create a long password — up to 255 characters — click Advanced, and then select an RC4 encryption type.