Security Use strong passwords that combine upper- and lowercase letters, numbers, and symbols. Weak passwords don't mix these elements. Strong password: Y6dh!et5. Weak password: House27. Use a strong password that you can remember so that you don't have to write it down.
- 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.
Tip
To create a long password— up to 255 characters— click Advanced, and then select an RC4 encryption type.