When selecting or changing your Hotmail/MSN Messenger password, the Microsoft Passport Network (version 3 of the well-know Passport service) will test its strength for you. Here are some tips for maximum password strength:

- Choose a password between 7 and 16 characters.

- Combine at least three different types of characters: UPPERCASE, lowercase, numbers (1, 2, 3...) and/or symbols (` ~ ! @ # $ % ^ & * ( ) _ + - = { } | [ ] : " ; ' < > ? , . /).

- Don't use common words or names, or close variations of them.

- A password shouldn't be the same as any of your four previous ones.

- A password shouldn't be a minor variation of your old password.