Passwords provide the first line of defense against unauthorized access to your computer, and a good password is often underestimated. Weak passwords provide attackers with easy access to your computer and network. Strong passwords are considerably harder to crack, even with the latest password-cracking software.
A strong password:
Is at least eight characters long.
Does not contain your user name, real name, or company name.
Does not contain a complete dictionary word.
Is significantly different from previous passwords. Passwords that change just slightly—such as Password1, Password2, Password3—are not strong.
Contains characters from each of the following groups:
Uppercase and/or lowercase letters.
Symbols (!,@,#,$,%, etc.)